feat: 事件字典 v3 白名单扩充——community 域 19 事件 + experiment_exposed 字典先行（T3-20 后端，ADR-020）

- EventDictionary 增补 20 个事件（iteration-3 报告 06 §1.5 白名单原样落地）：
  post 域 8（发布漏斗 started/draft_saved/publish_succeeded/failed、post_deleted、
  媒体上传三段逐文件漏斗）；feed 域 2（feed_viewed 浏览段聚合曝光 + feed_load_failed）；
  互动 8（like/unlike、favorite/unfavorite、comment 成败对、follow/unfollow）；
  platform 域 experiment_exposed（A/B 前置 #5，M4 启用字典先行）
- 字典 javadoc 同步 v3：社区隐私红线增量（§1.3 无正文/无内容 ID/无话题名/无媒体线索）
  与 pageName v3 页面族（§6.1 收编 4 + 新增 9，键级校验不变、后端零代码）
- EventDictionaryTest：每个新事件键集边界锁定 + §1.2/§1.4/§1.6 故意不设事件
  （post_impression/post_viewed/comment_create_started/单点互动 _failed/topic_follow）
- AnalyticsIntegrationTest：feed_viewed 聚合事件入库、post_liked 白名单外
  postId 剥离（红线 2）、post_impression 拒绝（§1.2 裁定 ingest 侧锁死）
- 测试 325 → 334（+9），openapi.yaml 无需变更（events 契约对事件名开放）

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docker-compose.yml

@@ -125,6 +125,10 @@ services:
       PATBOND_DB_USER: ${PATBOND_DB_USER:-patbond}
       PATBOND_DB_PASSWORD: ${PATBOND_DB_PASSWORD:?先运行 deploy/init-secrets.sh 生成 .env}
       PATBOND_JWT_PUBLIC_KEY: /run/patbond/keys/jwt-public.pem
+      # 作者公开资料（D3-9 方案 B）：走 user 服务 /internal 批量接口，
+      # 服务间共享密钥与 auth/user 同一值。
+      PATBOND_USER_SERVICE_URL: http://user:8082
+      PATBOND_INTERNAL_TOKEN: ${PATBOND_INTERNAL_TOKEN:?先运行 deploy/init-secrets.sh 生成 .env}
       # 媒体读取侧：帖子响应中图片 URL 的预签名 GET 与 user 服务同一凭证/同一
       # 客户端可达地址（本地 SigV4 计算，不直连 MinIO，无需 depends_on minio）。
       PATBOND_MINIO_PUBLIC_ENDPOINT: ${PATBOND_MINIO_PUBLIC_ENDPOINT:-http://127.0.0.1:9000}

patbond-auth/src/test/java/com/patbond/patbond/auth/contract/AuthContractConformanceTest.java

@@ -39,8 +39,8 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * T3-19（D3-8）：auth 域 6 个 M1 操作补进契约一致性保障，机制与
- * patbond-pet 的 ContractConformanceTest 同构——对冻结契约 v1.2.0（快照
- * {@code src/test/resources/contract/openapi-v1.2.0.yaml}，正典在 doc 仓
+ * patbond-pet 的 ContractConformanceTest 同构——对冻结契约 v1.3.0（快照
+ * {@code src/test/resources/contract/openapi-v1.3.0.yaml}，正典在 doc 仓
  * {@code docs/api/openapi.yaml}）逐操作真实发请求，用 {@link ContractValidator}
  * 严格校验响应结构，最后以全响应矩阵门禁兜底。
  *
@@ -314,10 +314,10 @@ class AuthContractConformanceTest {
     @Test
     @Order(98)
     void frozenSnapshotIsTheExpectedContractVersion() {
-        assertThat(CONTRACT.version()).isEqualTo("1.2.0");
-        assertThat(CONTRACT.paths()).hasSize(18);
-        assertThat(CONTRACT.operations()).hasSize(24);
-        assertThat(CONTRACT.schemas()).hasSize(45);
+        assertThat(CONTRACT.version()).isEqualTo("1.3.0");
+        assertThat(CONTRACT.paths()).hasSize(31);
+        assertThat(CONTRACT.operations()).hasSize(43);
+        assertThat(CONTRACT.schemas()).hasSize(72);
         assertThat(CONTRACT.operationsTagged(Set.of("auth", "user", "analytics")))
                 .containsExactlyInAnyOrderElementsOf(AUTH_OPERATIONS);
     }

patbond-auth/src/test/java/com/patbond/patbond/auth/contract/ContractValidator.java

@@ -10,6 +10,7 @@ import java.time.OffsetDateTime;
 import java.time.format.DateTimeParseException;
 import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -81,7 +82,7 @@ final class ContractValidator {
     }
 
     private void validate(Map<String, Object> rawSchema, JsonNode node, String loc, List<String> errors) {
-        Map<String, Object> schema = contract.resolve(rawSchema);
+        Map<String, Object> schema = effectiveSchema(rawSchema);
         if (node == null || node.isMissingNode()) {
             errors.add(loc + ": 字段缺失");
             return;
@@ -130,6 +131,32 @@ final class ContractValidator {
         }
     }
 
+    /**
+     * Resolves $refs and flattens the v1.3.0 {@code nullable + allOf: [$ref]}
+     * pattern into one plain schema (branch keys first, sibling keys — e.g.
+     * the outer {@code nullable} — win). The frozen contract only ever uses
+     * single-branch allOf, so a shallow merge is exact; overlapping
+     * {@code properties} across branches would need a deep merge and are not
+     * supported.
+     */
+    private Map<String, Object> effectiveSchema(Map<String, Object> rawSchema) {
+        Map<String, Object> schema = contract.resolve(rawSchema);
+        List<Object> allOf = list(schema, "allOf");
+        if (allOf == null) {
+            return schema;
+        }
+        Map<String, Object> merged = new LinkedHashMap<>();
+        for (Object branch : allOf) {
+            merged.putAll(effectiveSchema(cast(branch)));
+        }
+        schema.forEach((key, value) -> {
+            if (!"allOf".equals(key)) {
+                merged.put(key, value);
+            }
+        });
+        return merged;
+    }
+
     private void validateObject(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
         if (!node.isObject()) {
             errors.add(loc + ": 应为 object，实际 " + node.getNodeType());

patbond-auth/src/test/java/com/patbond/patbond/auth/contract/OpenApiContract.java

@@ -13,27 +13,30 @@ import java.util.Objects;
 import java.util.Set;
 
 /**
- * The frozen v1.2.0 OpenAPI contract, loaded from the test-resource snapshot
- * {@code /contract/openapi-v1.2.0.yaml}.
+ * The frozen v1.3.0 OpenAPI contract, loaded from the test-resource snapshot
+ * {@code /contract/openapi-v1.3.0.yaml}.
  *
  * <p><b>Sync discipline (T2-09, extended by T3-19)</b>: the canonical
  * contract lives in the doc repo at {@code docs/api/openapi.yaml}; this
  * snapshot is a byte-identical copy taken at freeze time, and this class is
  * the module-local copy of the pet module's contract framework (same
  * per-module duplication discipline as BearerAuthFilter). Whenever the
- * canonical contract changes, copy it here AND in patbond-pet under the new
- * version's file name and update both conformance tests (expected version +
- * snapshot counts). The guard test on {@code info.version} makes a forgotten
+ * canonical contract changes, copy it into every framework-carrying module
+ * (patbond-pet / patbond-auth / patbond-community / patbond-user) under the
+ * new version's file name and update each conformance test (expected version
+ * + snapshot counts). The guard test on {@code info.version} makes a forgotten
  * sync fail loudly in CI instead of silently testing against a stale
  * contract.
  *
  * <p>Only the subset of OpenAPI 3.0 this contract actually uses is supported:
  * local {@code #/} refs, plain types, {@code nullable}, {@code enum},
- * {@code required}, {@code properties}, {@code items} — no allOf/oneOf.
+ * {@code required}, {@code properties}, {@code items}, and the v1.3.0
+ * single-branch {@code nullable + allOf: [$ref]} pattern (merged in
+ * {@link ContractValidator}) — no oneOf/anyOf.
  */
 final class OpenApiContract {
 
-    static final String RESOURCE = "/contract/openapi-v1.2.0.yaml";
+    static final String RESOURCE = "/contract/openapi-v1.3.0.yaml";
 
     private static final Set<String> HTTP_METHODS =
             Set.of("get", "put", "post", "delete", "options", "head", "patch", "trace");

patbond-common/src/main/java/com/patbond/patbond/common/error/ErrorCode.java

@@ -26,9 +26,12 @@ public enum ErrorCode {
     VACCINATION_DOSE_EXISTS(40904, 409, "该疫苗系列剂次已登记"),
     IDEMPOTENCY_PAYLOAD_MISMATCH(40905, 409, "幂等键已用于不同请求"),
     MEDIA_NOT_FOUND(40405, 404, "媒体资源不存在"),
+    COMMENT_NOT_FOUND(40404, 404, "评论不存在"),
+    TARGET_USER_NOT_FOUND(40406, 404, "用户不存在"),
     VACCINATION_RULE_VIOLATION(42201, 422, "疫苗状态或日期约束不满足"),
     REMINDER_RULE_VIOLATION(42202, 422, "提醒状态或 completedAt 约束不满足"),
     MEDIA_NOT_READY(42203, 422, "媒体尚未就绪"),
+    FOLLOW_RULE_VIOLATION(42204, 422, "不能关注自己"),
     MEDIA_UPLOAD_STATE_INVALID(42205, 422, "上传状态不允许确认"),
     LOGIN_LOCKED(42300, 423, "登录失败次数过多，账号已临时锁定"),
     INTERNAL_ERROR(50000, 500, "服务器内部错误"),

patbond-community/pom.xml

@@ -39,6 +39,18 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-jdbc</artifactId>
         </dependency>
+        <!-- Author public profiles come from patbond-user's /internal batch
+             API (D3-9 方案 B), static direct URL per ADR-002. feign-hc5 for
+             the same reason as patbond-auth: the JDK default client loses
+             error bodies on some replies. -->
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-openfeign</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>io.github.openfeign</groupId>
+            <artifactId>feign-hc5</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.postgresql</groupId>
             <artifactId>postgresql</artifactId>

patbond-community/src/main/java/com/patbond/patbond/community/CommunityApplication.java

@@ -1,17 +1,21 @@
 package com.patbond.patbond.community;
 
+import com.patbond.patbond.community.config.CommunityFeignConfig;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.openfeign.EnableFeignClients;
 
 /**
  * Community feed, posts and interactions service (M3, ADR-017: the community
- * domain lives in its own Maven module on :8084). First-wave skeleton:
- * configuration wiring, datasource, RS256 bearer auth on /api/v1/** and a
- * liveness endpoint — business endpoints follow the contract work in the
- * next waves. The module only reads and writes the community schema
- * (author profile lookups follow the D3-9 plan later).
+ * domain lives in its own Maven module on :8084). Configuration wiring,
+ * datasource, RS256 bearer auth on /api/v1/**, the post lifecycle (T3-04)
+ * and the public feed (T3-05). The module only reads and writes the
+ * community schema (plus the ADR-017 read-only media.assets exception);
+ * author public profiles come from patbond-user's /internal batch API over
+ * Feign (D3-9 方案 B).
  */
 @SpringBootApplication
+@EnableFeignClients(defaultConfiguration = CommunityFeignConfig.class)
 public class CommunityApplication {
 
     public static void main(String[] args) {

patbond-community/src/main/java/com/patbond/patbond/community/access/UserExistenceGateway.java

@@ -0,0 +1,34 @@
+package com.patbond.patbond.community.access;
+
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.stereotype.Component;
+
+import java.util.UUID;
+
+/**
+ * Existence probe into identity.users for write gates that reference a
+ * user (follow target, comment @-reply target). Same-database read-only
+ * access under the ADR-017 exception — the user_follows/comments foreign
+ * keys already bind these schemas together, and a WRITE gate cannot ride
+ * the Feign profile path, whose degradation deliberately cannot tell
+ * "absent" from "unreachable". A soft-deleted (注销) user counts as absent.
+ */
+@Component
+public class UserExistenceGateway {
+
+    private final JdbcClient jdbcClient;
+
+    public UserExistenceGateway(JdbcClient jdbcClient) {
+        this.jdbcClient = jdbcClient;
+    }
+
+    public boolean existsActive(UUID userId) {
+        return jdbcClient.sql("""
+                        SELECT EXISTS (SELECT 1 FROM identity.users
+                                       WHERE id = :id AND deleted_at IS NULL)
+                        """)
+                .param("id", userId)
+                .query(Boolean.class)
+                .single();
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/author/AuthorProfileClient.java

@@ -0,0 +1,24 @@
+package com.patbond.patbond.community.author;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import java.util.List;
+
+/**
+ * Batch public-profile API of patbond-user, the identity schema owner
+ * (D3-9 方案 B; static direct URL per ADR-002). The X-Internal-Token header
+ * is attached by the interceptor in CommunityFeignConfig. Unknown or
+ * deleted ids are silently absent from the reply. {@code primary = false}
+ * only matters to tests (lets a stub take precedence); in production this
+ * is the sole candidate.
+ */
+@FeignClient(name = "patbond-user-profiles", url = "${patbond.user-service.url}", primary = false)
+public interface AuthorProfileClient {
+
+    /** @param ids comma-separated user ids, at most 50 per call */
+    @GetMapping("/internal/users/profiles")
+    ApiResponse<List<AuthorProfileDto>> profiles(@RequestParam("ids") String ids);
+}

patbond-community/src/main/java/com/patbond/patbond/community/author/AuthorProfileDto.java

@@ -0,0 +1,14 @@
+package com.patbond.patbond.community.author;
+
+import java.util.UUID;
+
+/**
+ * Wire shape of one profile in patbond-user's /internal/users/profiles
+ * reply (D3-9 方案 B): display name (nickname→username fallback already
+ * applied by the owning service) plus the avatar asset pointer. The avatar
+ * arrives as an id, not a URL — this service resolves it against
+ * media.assets (ADR-017 read-only exception) and signs a fresh presigned
+ * GET per response, so nothing cached here ever holds an expiring URL.
+ */
+public record AuthorProfileDto(UUID userId, String nickname, UUID avatarAssetId) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/author/AuthorProfileGateway.java

@@ -0,0 +1,145 @@
+package com.patbond.patbond.community.author;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.dto.AuthorSummaryResponse;
+import com.patbond.patbond.community.media.MediaAssetGateway;
+import com.patbond.patbond.community.media.MediaAssetRef;
+import com.patbond.patbond.community.media.MediaUrlSigner;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
+
+/**
+ * Author public-profile lookup (D3-9 方案 B): a batch Feign call to
+ * patbond-user's /internal/users/profiles behind a short-TTL in-process
+ * cache, plus local avatar resolution.
+ *
+ * <ul>
+ *   <li><b>Batch, never loop</b> — one call per ≤50 distinct cache-missed
+ *       authors (a feed page has ≤20 cards, so normally exactly one call,
+ *       and none on a warm cache).</li>
+ *   <li><b>Avatar</b> — travels as an asset id; resolved to bucket/key via
+ *       the ADR-017 read-only media.assets exception (ready assets only)
+ *       and signed fresh per response, so the cache stores no expiring
+ *       URL.</li>
+ *   <li><b>Degradation</b> — ANY lookup failure (user service down, slow,
+ *       or answering an error) logs one warning and leaves the ids
+ *       unresolved; callers render the id-only summary. Failures are never
+ *       cached, so the next request retries; the feed never 5xxes over a
+ *       profile lookup.</li>
+ * </ul>
+ */
+@Component
+public class AuthorProfileGateway {
+
+    private static final int MAX_BATCH = 50;
+    /** Expired entries are pruned opportunistically past this size. */
+    private static final int PRUNE_THRESHOLD = 10_000;
+
+    private static final Logger log = LoggerFactory.getLogger(AuthorProfileGateway.class);
+
+    private final AuthorProfileClient client;
+    private final MediaAssetGateway mediaAssetGateway;
+    private final MediaUrlSigner mediaUrlSigner;
+    private final AuthorProfileProperties properties;
+    private final ConcurrentHashMap<UUID, CacheEntry> cache = new ConcurrentHashMap<>();
+
+    public AuthorProfileGateway(AuthorProfileClient client, MediaAssetGateway mediaAssetGateway,
+                                MediaUrlSigner mediaUrlSigner, AuthorProfileProperties properties) {
+        this.client = client;
+        this.mediaAssetGateway = mediaAssetGateway;
+        this.mediaUrlSigner = mediaUrlSigner;
+        this.properties = properties;
+    }
+
+    /**
+     * Summaries for the given authors, avatar URLs signed fresh. Ids that
+     * could not be resolved (lookup degraded, or the user no longer exists)
+     * are absent — callers fall back to
+     * {@link AuthorSummaryResponse#idOnly}.
+     */
+    public Map<UUID, AuthorSummaryResponse> summarize(Collection<UUID> userIds) {
+        if (userIds.isEmpty()) {
+            return Map.of();
+        }
+        long now = System.nanoTime();
+        Map<UUID, AuthorRef> resolved = new HashMap<>();
+        List<UUID> misses = new ArrayList<>();
+        for (UUID id : new LinkedHashSet<>(userIds)) {
+            CacheEntry entry = cache.get(id);
+            if (entry != null && entry.expiresAtNanos() - now > 0) {
+                resolved.put(id, entry.ref());
+            } else {
+                misses.add(id);
+            }
+        }
+        if (!misses.isEmpty()) {
+            fetchInto(resolved, misses, now);
+        }
+        Map<UUID, AuthorSummaryResponse> summaries = new HashMap<>();
+        resolved.forEach((id, ref) -> summaries.put(id, new AuthorSummaryResponse(
+                id, ref.nickname(), mediaUrlSigner.signGet(ref.avatarBucket(), ref.avatarObjectKey()))));
+        return summaries;
+    }
+
+    private void fetchInto(Map<UUID, AuthorRef> resolved, List<UUID> misses, long now) {
+        List<AuthorProfileDto> profiles = new ArrayList<>();
+        try {
+            for (int i = 0; i < misses.size(); i += MAX_BATCH) {
+                List<UUID> chunk = misses.subList(i, Math.min(i + MAX_BATCH, misses.size()));
+                ApiResponse<List<AuthorProfileDto>> reply = client.profiles(
+                        chunk.stream().map(UUID::toString).collect(Collectors.joining(",")));
+                if (reply != null && reply.getData() != null) {
+                    profiles.addAll(reply.getData());
+                }
+            }
+        } catch (RuntimeException e) {
+            // Chunks fetched before the failure still count below.
+            log.warn("作者公开资料获取失败，本次响应对未解析作者降级为 authorId 保底: {}",
+                    e.toString());
+        }
+        if (profiles.isEmpty()) {
+            return;
+        }
+        Set<UUID> assetIds = profiles.stream()
+                .map(AuthorProfileDto::avatarAssetId)
+                .filter(Objects::nonNull)
+                .collect(Collectors.toSet());
+        Map<UUID, MediaAssetRef> assets = assetIds.isEmpty()
+                ? Map.of()
+                : mediaAssetGateway.findByIds(assetIds);
+        long expiresAt = now + properties.getCacheTtl().toNanos();
+        for (AuthorProfileDto profile : profiles) {
+            MediaAssetRef asset = profile.avatarAssetId() == null
+                    ? null
+                    : assets.get(profile.avatarAssetId());
+            boolean ready = asset != null && "ready".equals(asset.status());
+            AuthorRef ref = new AuthorRef(profile.nickname(),
+                    ready ? asset.bucket() : null,
+                    ready ? asset.objectKey() : null);
+            cache.put(profile.userId(), new CacheEntry(ref, expiresAt));
+            resolved.put(profile.userId(), ref);
+        }
+        if (cache.size() > PRUNE_THRESHOLD) {
+            cache.values().removeIf(entry -> entry.expiresAtNanos() - now <= 0);
+        }
+    }
+
+    private record AuthorRef(String nickname, String avatarBucket, String avatarObjectKey) {
+    }
+
+    private record CacheEntry(AuthorRef ref, long expiresAtNanos) {
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/author/AuthorProfileProperties.java

@@ -0,0 +1,26 @@
+package com.patbond.patbond.community.author;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+import java.time.Duration;
+
+/**
+ * Knobs of the author-profile lookup (D3-9 方案 B): a short in-process TTL
+ * cache in front of patbond-user's /internal batch API. 60 s is the frozen
+ * default — long enough to absorb feed scrolling and refresh bursts,
+ * short enough that a nickname/avatar change propagates within a minute.
+ */
+@ConfigurationProperties(prefix = "patbond.author-profile")
+public class AuthorProfileProperties {
+
+    /** How long one resolved profile stays in the in-process cache. */
+    private Duration cacheTtl = Duration.ofSeconds(60);
+
+    public Duration getCacheTtl() {
+        return cacheTtl;
+    }
+
+    public void setCacheTtl(Duration value) {
+        this.cacheTtl = value;
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/config/CommunityFeignConfig.java

@@ -0,0 +1,35 @@
+package com.patbond.patbond.community.config;
+
+import feign.Request;
+import feign.RequestInterceptor;
+import org.springframework.context.annotation.Bean;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Feign child-context beans, registered via
+ * {@code @EnableFeignClients(defaultConfiguration = …)} — deliberately not
+ * a @Configuration, same reasoning as patbond-auth's FeignInternalConfig
+ * (a component-scanned bean would land in the parent context and be
+ * shadowed by the child's defaults).
+ *
+ * <p>No ErrorDecoder on purpose: the only Feign consumer here is the author
+ * profile lookup, whose gateway degrades on ANY failure instead of
+ * propagating it — a downstream business error is as much "no profile" as a
+ * connection refusal. Timeouts are tight because this call sits on the feed
+ * read path: a hung patbond-user must cost one bounded stall, not an
+ * unbounded one (connection refused already fails fast on its own).</p>
+ */
+public class CommunityFeignConfig {
+
+    /** Presents the shared service secret on every call to patbond-user. */
+    @Bean
+    public RequestInterceptor internalTokenInterceptor(CommunitySecurityProperties properties) {
+        return template -> template.header("X-Internal-Token", properties.getInternalToken());
+    }
+
+    @Bean
+    public Request.Options feignOptions() {
+        return new Request.Options(1, TimeUnit.SECONDS, 2, TimeUnit.SECONDS, true);
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/config/CommunitySecurityProperties.java

@@ -3,16 +3,32 @@ package com.patbond.patbond.community.config;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
- * Security knobs of the community service: only the RS256 public key for
+ * Security knobs of the community service: the RS256 public key for
  * verifying access tokens issued by patbond-auth (same contract as
- * patbond-user/pet's {@code patbond.jwt.public-key}). No /internal routes
- * exist here yet, so no service token property.
+ * patbond-user/pet's {@code patbond.jwt.public-key}), and the shared
+ * service secret presented on outbound /internal/** calls to patbond-user
+ * (D3-9 方案 B author-profile lookups — this service still exposes no
+ * /internal routes of its own).
  */
 @ConfigurationProperties(prefix = "patbond")
 public class CommunitySecurityProperties {
 
+    /**
+     * Shared secret sent as X-Internal-Token on calls to patbond-user's
+     * /internal/** API; must equal the value patbond-user expects.
+     */
+    private String internalToken;
+
     private final Jwt jwt = new Jwt();
 
+    public String getInternalToken() {
+        return internalToken;
+    }
+
+    public void setInternalToken(String value) {
+        this.internalToken = value;
+    }
+
     public Jwt getJwt() {
         return jwt;
     }

patbond-community/src/main/java/com/patbond/patbond/community/config/SecurityConfig.java

@@ -1,6 +1,7 @@
 package com.patbond.patbond.community.config;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.patbond.patbond.community.author.AuthorProfileProperties;
 import com.patbond.patbond.community.security.BearerAuthFilter;
 import com.patbond.patbond.community.security.JwtVerifier;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
@@ -15,7 +16,7 @@ import org.springframework.context.annotation.Configuration;
  * unauthenticated.
  */
 @Configuration
-@EnableConfigurationProperties(CommunitySecurityProperties.class)
+@EnableConfigurationProperties({CommunitySecurityProperties.class, AuthorProfileProperties.class})
 public class SecurityConfig {
 
     @Bean

patbond-community/src/main/java/com/patbond/patbond/community/controller/CommentController.java

@@ -0,0 +1,71 @@
+package com.patbond.patbond.community.controller;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.dto.CommentResponse;
+import com.patbond.patbond.community.dto.CreateCommentRequest;
+import com.patbond.patbond.community.dto.CursorPage;
+import com.patbond.patbond.community.security.BearerAuthFilter;
+import com.patbond.patbond.community.service.CommentService;
+import jakarta.validation.Valid;
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
+import org.springframework.http.HttpStatus;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+/**
+ * Flat comment endpoints (T3-07). Delete rides the top-level short path
+ * (commentId is globally unique — the pets-domain precedent); create
+ * carries a MANDATORY Idempotency-Key (ADR-019). All permission and error
+ * semantics live in CommentService.
+ */
+@RestController
+@Validated
+public class CommentController {
+
+    private final CommentService commentService;
+
+    public CommentController(CommentService commentService) {
+        this.commentService = commentService;
+    }
+
+    @GetMapping("/api/v1/posts/{postId}/comments")
+    public ApiResponse<CursorPage<CommentResponse>> list(
+            @PathVariable UUID postId,
+            @RequestParam(defaultValue = "20")
+            @Min(value = 1, message = "limit 最小为 1")
+            @Max(value = 100, message = "limit 最大为 100")
+            int limit,
+            @RequestParam(required = false) String cursor) {
+        return ApiResponse.success(commentService.list(postId, limit, cursor));
+    }
+
+    @PostMapping("/api/v1/posts/{postId}/comments")
+    @ResponseStatus(HttpStatus.CREATED)
+    public ApiResponse<CommentResponse> create(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID postId,
+            @RequestHeader("Idempotency-Key") String idempotencyKey,
+            @Valid @RequestBody CreateCommentRequest request) {
+        return ApiResponse.success(commentService.create(userId, postId, idempotencyKey, request));
+    }
+
+    @DeleteMapping("/api/v1/comments/{commentId}")
+    public ApiResponse<Void> delete(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID commentId) {
+        commentService.delete(userId, commentId);
+        return ApiResponse.success(null);
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/controller/FeedController.java

@@ -0,0 +1,43 @@
+package com.patbond.patbond.community.controller;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.dto.CursorPage;
+import com.patbond.patbond.community.dto.FeedCardResponse;
+import com.patbond.patbond.community.security.BearerAuthFilter;
+import com.patbond.patbond.community.service.FeedService;
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+/**
+ * Public feed endpoint (T3-05). Authenticated like every /api/v1 route —
+ * the viewer identity feeds likedByMe/bookmarkedByMe; the feed content
+ * itself is the same for everyone (published + public only).
+ */
+@RestController
+@Validated
+public class FeedController {
+
+    private final FeedService feedService;
+
+    public FeedController(FeedService feedService) {
+        this.feedService = feedService;
+    }
+
+    @GetMapping("/api/v1/feed")
+    public ApiResponse<CursorPage<FeedCardResponse>> feed(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @RequestParam(defaultValue = "20")
+            @Min(value = 1, message = "limit 最小为 1")
+            @Max(value = 100, message = "limit 最大为 100")
+            int limit,
+            @RequestParam(required = false) String cursor) {
+        return ApiResponse.success(feedService.list(userId, limit, cursor));
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/controller/FollowController.java

@@ -0,0 +1,51 @@
+package com.patbond.patbond.community.controller;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.dto.FollowStateResponse;
+import com.patbond.patbond.community.dto.FollowStatsResponse;
+import com.patbond.patbond.community.security.BearerAuthFilter;
+import com.patbond.patbond.community.service.FollowService;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+/**
+ * The ADR-018 minimal follow surface (T3-07): idempotent follow/unfollow
+ * plus the numbers endpoint. Follower/following LISTS are deliberately not
+ * in M3.
+ */
+@RestController
+public class FollowController {
+
+    private final FollowService followService;
+
+    public FollowController(FollowService followService) {
+        this.followService = followService;
+    }
+
+    @PutMapping("/api/v1/users/{userId}/follow")
+    public ApiResponse<FollowStateResponse> follow(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID callerId,
+            @PathVariable UUID userId) {
+        return ApiResponse.success(followService.follow(callerId, userId));
+    }
+
+    @DeleteMapping("/api/v1/users/{userId}/follow")
+    public ApiResponse<FollowStateResponse> unfollow(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID callerId,
+            @PathVariable UUID userId) {
+        return ApiResponse.success(followService.unfollow(callerId, userId));
+    }
+
+    @GetMapping("/api/v1/users/{userId}/follow-stats")
+    public ApiResponse<FollowStatsResponse> stats(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID callerId,
+            @PathVariable UUID userId) {
+        return ApiResponse.success(followService.stats(callerId, userId));
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/controller/InteractionController.java

@@ -0,0 +1,79 @@
+package com.patbond.patbond.community.controller;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.dto.BookmarkStateResponse;
+import com.patbond.patbond.community.dto.CursorPage;
+import com.patbond.patbond.community.dto.FeedCardResponse;
+import com.patbond.patbond.community.dto.LikeStateResponse;
+import com.patbond.patbond.community.security.BearerAuthFilter;
+import com.patbond.patbond.community.service.FeedService;
+import com.patbond.patbond.community.service.InteractionService;
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestAttribute;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.UUID;
+
+/**
+ * Binary post interactions (T3-06): PUT/DELETE idempotent like and
+ * bookmark, each answering the authoritative terminal state, plus the
+ * my-bookmarks list whose items reuse the feed card shape.
+ */
+@RestController
+@Validated
+public class InteractionController {
+
+    private final InteractionService interactionService;
+    private final FeedService feedService;
+
+    public InteractionController(InteractionService interactionService, FeedService feedService) {
+        this.interactionService = interactionService;
+        this.feedService = feedService;
+    }
+
+    @PutMapping("/api/v1/posts/{postId}/like")
+    public ApiResponse<LikeStateResponse> like(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID postId) {
+        return ApiResponse.success(interactionService.like(userId, postId));
+    }
+
+    @DeleteMapping("/api/v1/posts/{postId}/like")
+    public ApiResponse<LikeStateResponse> unlike(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID postId) {
+        return ApiResponse.success(interactionService.unlike(userId, postId));
+    }
+
+    @PutMapping("/api/v1/posts/{postId}/bookmark")
+    public ApiResponse<BookmarkStateResponse> bookmark(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID postId) {
+        return ApiResponse.success(interactionService.bookmark(userId, postId));
+    }
+
+    @DeleteMapping("/api/v1/posts/{postId}/bookmark")
+    public ApiResponse<BookmarkStateResponse> unbookmark(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @PathVariable UUID postId) {
+        return ApiResponse.success(interactionService.unbookmark(userId, postId));
+    }
+
+    @GetMapping("/api/v1/me/bookmarks")
+    public ApiResponse<CursorPage<FeedCardResponse>> myBookmarks(
+            @RequestAttribute(BearerAuthFilter.USER_ID_ATTRIBUTE) UUID userId,
+            @RequestParam(defaultValue = "20")
+            @Min(value = 1, message = "limit 最小为 1")
+            @Max(value = 100, message = "limit 最大为 100")
+            int limit,
+            @RequestParam(required = false) String cursor) {
+        return ApiResponse.success(feedService.listBookmarked(userId, limit, cursor));
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/AuthorSummaryResponse.java

@@ -0,0 +1,21 @@
+package com.patbond.patbond.community.dto;
+
+import java.util.UUID;
+
+/**
+ * Author public summary embedded in post/feed/comment responses (D3-9).
+ * {@code nickname} carries the nickname→username fallback applied by
+ * patbond-user, so clients never assemble a display name themselves;
+ * {@code avatarUrl} is a fresh presigned GET (null when the author has no
+ * ready avatar, or when object storage is unconfigured — clients show a
+ * placeholder). The degraded shape — profile service unreachable, or the
+ * author since deleted — keeps only {@code userId} and nulls the rest
+ * (authorId 保底：the feed never 5xxes over a profile lookup).
+ */
+public record AuthorSummaryResponse(UUID userId, String nickname, String avatarUrl) {
+
+    /** The degraded / tombstone shape: id only, client renders placeholders. */
+    public static AuthorSummaryResponse idOnly(UUID userId) {
+        return new AuthorSummaryResponse(userId, null, null);
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/BookmarkStateResponse.java

@@ -0,0 +1,5 @@
+package com.patbond.patbond.community.dto;
+
+/** Authoritative post-write bookmark state — isomorphic to {@link LikeStateResponse}. */
+public record BookmarkStateResponse(boolean bookmarked, long bookmarkCount) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/CommentResponse.java

@@ -0,0 +1,19 @@
+package com.patbond.patbond.community.dto;
+
+import java.time.OffsetDateTime;
+import java.util.UUID;
+
+/**
+ * One flat comment (T3-07 定型): the author and the optional @-reply target
+ * both travel as the D3-9 AuthorSummary shape, resolved through the same
+ * batch profile gateway as posts, so a degraded profile service renders
+ * id-only summaries here too and never fails the request.
+ */
+public record CommentResponse(
+        UUID id,
+        UUID postId,
+        AuthorSummaryResponse author,
+        AuthorSummaryResponse replyToUser,
+        String content,
+        OffsetDateTime createdAt) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/CreateCommentRequest.java

@@ -0,0 +1,38 @@
+package com.patbond.patbond.community.dto;
+
+import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.Size;
+
+import java.util.UUID;
+
+/**
+ * POST /api/v1/posts/{postId}/comments. Content width mirrors
+ * ck_comments_content (1~2000 after trim); {@code replyToUserId} is the
+ * optional flat @-reply target (single level, no parentCommentId — ADR-018
+ * rules out nested threads).
+ */
+public class CreateCommentRequest {
+
+    @NotBlank(message = "content 不能为空")
+    @Size(max = 2000, message = "content 最长 2000 字符")
+    private String content;
+
+    /** Optional @-reply target; must be an existing active user (40406). */
+    private UUID replyToUserId;
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public UUID getReplyToUserId() {
+        return replyToUserId;
+    }
+
+    public void setReplyToUserId(UUID replyToUserId) {
+        this.replyToUserId = replyToUserId;
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/FeedCardResponse.java

@@ -0,0 +1,29 @@
+package com.patbond.patbond.community.dto;
+
+import java.time.OffsetDateTime;
+import java.util.UUID;
+
+/**
+ * One public-feed card (T3-05 定型, the FeedCard freeze input): the Post
+ * shape trimmed for list rendering — content cut to a 200-code-point
+ * preview, the media set reduced to the cover item plus a count, counts
+ * read from the posts table's denormalized columns. {@code coverImage} is
+ * null exactly for text-only posts (T3-04 guarantees a unique is_cover row
+ * whenever media exist); {@code publishedAt} is never null here (the feed
+ * predicate admits published posts only).
+ */
+public record FeedCardResponse(
+        UUID id,
+        AuthorSummaryResponse author,
+        String category,
+        String title,
+        String contentPreview,
+        PostMediaItemResponse coverImage,
+        int mediaCount,
+        long likeCount,
+        long commentCount,
+        long bookmarkCount,
+        boolean likedByMe,
+        boolean bookmarkedByMe,
+        OffsetDateTime publishedAt) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/FollowStateResponse.java

@@ -0,0 +1,10 @@
+package com.patbond.patbond.community.dto;
+
+/**
+ * Authoritative post-write follow state; {@code followerCount} is the
+ * TARGET user's follower count (real-time COUNT — user_follows has no
+ * denormalized counter column, and the double index keeps both directions
+ * cheap).
+ */
+public record FollowStateResponse(boolean following, long followerCount) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/FollowStatsResponse.java

@@ -0,0 +1,9 @@
+package com.patbond.patbond.community.dto;
+
+/**
+ * GET /api/v1/users/{userId}/follow-stats — the ADR-018 minimal "numbers"
+ * endpoint. {@code followedByMe} is the caller's view; asking about oneself
+ * yields false (a self-follow row cannot exist, ck_user_follows_self).
+ */
+public record FollowStatsResponse(long followerCount, long followingCount, boolean followedByMe) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/LikeStateResponse.java

@@ -0,0 +1,10 @@
+package com.patbond.patbond.community.dto;
+
+/**
+ * Authoritative post-write like state (草案定型): a PUT answers
+ * {@code liked=true} and a DELETE {@code liked=false} regardless of whether
+ * the call changed anything; {@code likeCount} is the count as of this
+ * write's transaction, the value optimistic clients reconcile against.
+ */
+public record LikeStateResponse(boolean liked, long likeCount) {
+}

patbond-community/src/main/java/com/patbond/patbond/community/dto/PostResponse.java

@@ -5,16 +5,16 @@ import java.util.List;
 import java.util.UUID;
 
 /**
- * Full post shape (detail / my-posts list / write responses). Deviation from
- * the contract draft, recorded for the T3-10 freeze: the draft's
- * {@code author: AuthorSummary} is placeheld by {@code authorId} until T3-05
- * lands the public-profile aggregation (工单口径：author 字段可先占位
- * authorId). Trimmed fields (region/generationJob/topics …) do not appear at
- * all (ADR-018 + ADR-010 precedent).
+ * Full post shape (detail / my-posts list / write responses). The T3-04
+ * {@code authorId} placeholder is gone: {@code author} is the D3-9
+ * AuthorSummary, degraded to its id-only shape when the profile lookup is
+ * unavailable (contract deviation #1 closed by T3-05). Trimmed fields
+ * (region/generationJob/topics …) do not appear at all (ADR-018 + ADR-010
+ * precedent).
  */
 public record PostResponse(
         UUID id,
-        UUID authorId,
+        AuthorSummaryResponse author,
         UUID petId,
         String category,
         String title,

patbond-community/src/main/java/com/patbond/patbond/community/repository/CommentRepository.java

@@ -0,0 +1,145 @@
+package com.patbond.patbond.community.repository;
+
+import com.patbond.patbond.community.support.CommentCursor;
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.stereotype.Repository;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.time.OffsetDateTime;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+/**
+ * community.comments access. Post visibility and authorship decisions live
+ * in CommentService; every query here filters on the comment's own state
+ * only (status='visible' is the single liveness predicate — 'hidden' has no
+ * producing endpoint in M3 and 'deleted' pairs with deleted_at,
+ * ck_comments_deleted).
+ */
+@Repository
+public class CommentRepository {
+
+    private static final String SELECT_COMMENT = """
+            SELECT c.id, c.post_id, c.author_user_id, c.reply_to_user_id, c.content,
+                   c.status, c.request_hash, c.created_at, c.deleted_at
+            FROM community.comments c
+            """;
+
+    private final JdbcClient jdbcClient;
+
+    public CommentRepository(JdbcClient jdbcClient) {
+        this.jdbcClient = jdbcClient;
+    }
+
+    /**
+     * Inserts one comment; the conflict target is the (author_user_id,
+     * client_request_id) unique constraint, so a keyed replay is a no-op and
+     * the caller settles retry-vs-mismatch on the stored request_hash
+     * (ADR-019, same shape as posts).
+     *
+     * @return rows inserted — 0 means this author already used the key
+     */
+    public int insertComment(UUID id, UUID postId, UUID authorUserId, UUID replyToUserId,
+                             String content, String clientRequestId, byte[] requestHash) {
+        return jdbcClient.sql("""
+                        INSERT INTO community.comments
+                            (id, post_id, author_user_id, reply_to_user_id, content,
+                             client_request_id, request_hash)
+                        VALUES (:id, :postId, :authorUserId, :replyToUserId, :content,
+                                :clientRequestId, :requestHash)
+                        ON CONFLICT (author_user_id, client_request_id) DO NOTHING
+                        """)
+                .param("id", id)
+                .param("postId", postId)
+                .param("authorUserId", authorUserId)
+                .param("replyToUserId", replyToUserId)
+                .param("content", content)
+                .param("clientRequestId", clientRequestId)
+                .param("requestHash", requestHash)
+                .update();
+    }
+
+    /** First-write row for a (author, Idempotency-Key) pair, deleted or not. */
+    public Optional<CommentRow> findByAuthorAndClientRequestId(UUID authorUserId,
+                                                               String clientRequestId) {
+        return jdbcClient.sql(SELECT_COMMENT
+                        + " WHERE c.author_user_id = :authorUserId"
+                        + " AND c.client_request_id = :clientRequestId")
+                .param("authorUserId", authorUserId)
+                .param("clientRequestId", clientRequestId)
+                .query(CommentRepository::mapComment)
+                .optional();
+    }
+
+    /**
+     * Locks the visible row for the delete transition: concurrent deletes
+     * of the same comment serialize here, so the status flip — and with it
+     * the comment_count decrement — happens exactly once.
+     */
+    public Optional<CommentRow> lockVisibleById(UUID id) {
+        return jdbcClient.sql(SELECT_COMMENT + " WHERE c.id = :id AND c.status = 'visible' FOR UPDATE")
+                .param("id", id)
+                .query(CommentRepository::mapComment)
+                .optional();
+    }
+
+    /** The soft-delete transition; deleted_at pairs with status (ck_comments_deleted). */
+    public int softDelete(UUID id) {
+        return jdbcClient.sql("""
+                        UPDATE community.comments
+                        SET status = 'deleted', deleted_at = now()
+                        WHERE id = :id AND status = 'visible'
+                        """)
+                .param("id", id)
+                .update();
+    }
+
+    /**
+     * One page of a post's visible comments in (created_at DESC, id DESC) —
+     * the exact key of ix_comments_post_created. The caller asks for
+     * limit+1 rows to learn whether more exist.
+     */
+    public List<CommentRow> pageByPost(UUID postId, CommentCursor after, int limitPlusOne) {
+        String sql = SELECT_COMMENT + " WHERE c.post_id = :postId AND c.status = 'visible'";
+        if (after != null) {
+            sql += " AND (c.created_at, c.id) < (:cursorCreatedAt, :cursorId)";
+        }
+        sql += " ORDER BY c.created_at DESC, c.id DESC LIMIT :limit";
+        var spec = jdbcClient.sql(sql)
+                .param("postId", postId)
+                .param("limit", limitPlusOne);
+        if (after != null) {
+            spec = spec.param("cursorCreatedAt", after.createdAt())
+                    .param("cursorId", after.id());
+        }
+        return spec.query(CommentRepository::mapComment).list();
+    }
+
+    private static CommentRow mapComment(ResultSet rs, int rowNum) throws SQLException {
+        return new CommentRow(
+                rs.getObject("id", UUID.class),
+                rs.getObject("post_id", UUID.class),
+                rs.getObject("author_user_id", UUID.class),
+                rs.getObject("reply_to_user_id", UUID.class),
+                rs.getString("content"),
+                rs.getString("status"),
+                rs.getBytes("request_hash"),
+                rs.getObject("created_at", OffsetDateTime.class),
+                rs.getObject("deleted_at", OffsetDateTime.class));
+    }
+
+    /** One comments row; requestHash carries the ADR-019 replay comparison. */
+    public record CommentRow(
+            UUID id,
+            UUID postId,
+            UUID authorUserId,
+            UUID replyToUserId,
+            String content,
+            String status,
+            byte[] requestHash,
+            OffsetDateTime createdAt,
+            OffsetDateTime deletedAt) {
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/repository/InteractionRepository.java

@@ -0,0 +1,202 @@
+package com.patbond.patbond.community.repository;
+
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.stereotype.Repository;
+
+import java.util.UUID;
+
+/**
+ * community.post_likes / post_bookmarks / user_follows access, plus the
+ * denormalized counter writes on community.posts. The invariant every
+ * caller must hold (工单验收硬项): a counter column moves IN THE SAME
+ * TRANSACTION as its relation row, and only by the number of rows the
+ * relation write actually changed — {@code ON CONFLICT DO NOTHING} inserts
+ * and conditional deletes report that number, so concurrent duplicates
+ * converge on the composite primary key and never double-count.
+ */
+@Repository
+public class InteractionRepository {
+
+    private final JdbcClient jdbcClient;
+
+    public InteractionRepository(JdbcClient jdbcClient) {
+        this.jdbcClient = jdbcClient;
+    }
+
+    /**
+     * The interaction gate: likes, bookmarks and comments attach to the
+     * PUBLIC face of a post only — published and live. Drafts (the
+     * author's own included), hidden/archived and soft-deleted posts all
+     * fail this probe and answer the byte-identical 404/40403.
+     */
+    public boolean isInteractable(UUID postId) {
+        return jdbcClient.sql("""
+                        SELECT EXISTS (SELECT 1 FROM community.posts
+                                       WHERE id = :id AND status = 'published'
+                                       AND deleted_at IS NULL)
+                        """)
+                .param("id", postId)
+                .query(Boolean.class)
+                .single();
+    }
+
+    /** @return rows inserted — 0 when the like already existed */
+    public int insertLike(UUID postId, UUID userId) {
+        return jdbcClient.sql("""
+                        INSERT INTO community.post_likes (post_id, user_id)
+                        VALUES (:postId, :userId)
+                        ON CONFLICT (post_id, user_id) DO NOTHING
+                        """)
+                .param("postId", postId)
+                .param("userId", userId)
+                .update();
+    }
+
+    /** @return rows deleted — 0 when there was nothing to cancel */
+    public int deleteLike(UUID postId, UUID userId) {
+        return jdbcClient.sql("""
+                        DELETE FROM community.post_likes
+                        WHERE post_id = :postId AND user_id = :userId
+                        """)
+                .param("postId", postId)
+                .param("userId", userId)
+                .update();
+    }
+
+    /** @return rows inserted — 0 when the bookmark already existed */
+    public int insertBookmark(UUID postId, UUID userId) {
+        return jdbcClient.sql("""
+                        INSERT INTO community.post_bookmarks (post_id, user_id)
+                        VALUES (:postId, :userId)
+                        ON CONFLICT (post_id, user_id) DO NOTHING
+                        """)
+                .param("postId", postId)
+                .param("userId", userId)
+                .update();
+    }
+
+    /** @return rows deleted — 0 when there was nothing to cancel */
+    public int deleteBookmark(UUID postId, UUID userId) {
+        return jdbcClient.sql("""
+                        DELETE FROM community.post_bookmarks
+                        WHERE post_id = :postId AND user_id = :userId
+                        """)
+                .param("postId", postId)
+                .param("userId", userId)
+                .update();
+    }
+
+    /**
+     * Moves like_count by delta and returns the resulting value — the
+     * authoritative count the write response carries. Callers pass the row
+     * count their relation write reported; a zero delta must instead read
+     * via {@link #likeCount} so a no-op replay takes no row lock and does
+     * not touch updated_at.
+     */
+    public long bumpLikeCount(UUID postId, int delta) {
+        return jdbcClient.sql("""
+                        UPDATE community.posts SET like_count = like_count + :delta
+                        WHERE id = :id
+                        RETURNING like_count
+                        """)
+                .param("id", postId)
+                .param("delta", delta)
+                .query(Long.class)
+                .single();
+    }
+
+    public long bumpBookmarkCount(UUID postId, int delta) {
+        return jdbcClient.sql("""
+                        UPDATE community.posts SET bookmark_count = bookmark_count + :delta
+                        WHERE id = :id
+                        RETURNING bookmark_count
+                        """)
+                .param("id", postId)
+                .param("delta", delta)
+                .query(Long.class)
+                .single();
+    }
+
+    public long bumpCommentCount(UUID postId, int delta) {
+        return jdbcClient.sql("""
+                        UPDATE community.posts SET comment_count = comment_count + :delta
+                        WHERE id = :id
+                        RETURNING comment_count
+                        """)
+                .param("id", postId)
+                .param("delta", delta)
+                .query(Long.class)
+                .single();
+    }
+
+    public long likeCount(UUID postId) {
+        return jdbcClient.sql("SELECT like_count FROM community.posts WHERE id = :id")
+                .param("id", postId)
+                .query(Long.class)
+                .single();
+    }
+
+    public long bookmarkCount(UUID postId) {
+        return jdbcClient.sql("SELECT bookmark_count FROM community.posts WHERE id = :id")
+                .param("id", postId)
+                .query(Long.class)
+                .single();
+    }
+
+    /** @return rows inserted — 0 when the follow already existed */
+    public int insertFollow(UUID followerUserId, UUID followeeUserId) {
+        return jdbcClient.sql("""
+                        INSERT INTO community.user_follows (follower_user_id, followee_user_id)
+                        VALUES (:follower, :followee)
+                        ON CONFLICT (follower_user_id, followee_user_id) DO NOTHING
+                        """)
+                .param("follower", followerUserId)
+                .param("followee", followeeUserId)
+                .update();
+    }
+
+    /** @return rows deleted — 0 when there was nothing to cancel */
+    public int deleteFollow(UUID followerUserId, UUID followeeUserId) {
+        return jdbcClient.sql("""
+                        DELETE FROM community.user_follows
+                        WHERE follower_user_id = :follower AND followee_user_id = :followee
+                        """)
+                .param("follower", followerUserId)
+                .param("followee", followeeUserId)
+                .update();
+    }
+
+    /** Real-time follower count of a user — ix_user_follows_followee. */
+    public long countFollowers(UUID userId) {
+        return jdbcClient.sql("""
+                        SELECT count(*) FROM community.user_follows
+                        WHERE followee_user_id = :userId
+                        """)
+                .param("userId", userId)
+                .query(Long.class)
+                .single();
+    }
+
+    /** Real-time following count of a user — the primary key prefix. */
+    public long countFollowing(UUID userId) {
+        return jdbcClient.sql("""
+                        SELECT count(*) FROM community.user_follows
+                        WHERE follower_user_id = :userId
+                        """)
+                .param("userId", userId)
+                .query(Long.class)
+                .single();
+    }
+
+    public boolean followExists(UUID followerUserId, UUID followeeUserId) {
+        return jdbcClient.sql("""
+                        SELECT EXISTS (SELECT 1 FROM community.user_follows
+                                       WHERE follower_user_id = :follower
+                                       AND followee_user_id = :followee)
+                        """)
+                .param("follower", followerUserId)
+                .param("followee", followeeUserId)
+                .query(Boolean.class)
+                .single();
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/repository/PostRepository.java

@@ -1,5 +1,7 @@
 package com.patbond.patbond.community.repository;
 
+import com.patbond.patbond.community.support.BookmarkCursor;
+import com.patbond.patbond.community.support.FeedCursor;
 import com.patbond.patbond.community.support.PostCursor;
 import org.springframework.jdbc.core.simple.JdbcClient;
 import org.springframework.stereotype.Repository;
@@ -200,6 +202,74 @@ public class PostRepository {
         return spec.query(PostRepository::mapPost).list();
     }
 
+    /**
+     * One public-feed page in (published_at DESC, id DESC) — the exact key
+     * and predicate of the ix_posts_feed partial index. The explicit
+     * {@code deleted_at IS NULL} is belt-and-braces: softDelete parks
+     * published rows as 'archived', so status='published' already implies
+     * live (ck_posts_publish_state), and the planner still matches the
+     * partial index. The caller asks for limit+1 rows to learn whether more
+     * exist.
+     */
+    public List<PostRow> pageFeed(UUID viewerId, FeedCursor after, int limitPlusOne) {
+        String sql = SELECT_POST + """
+                 WHERE p.status = 'published' AND p.visibility = 'public'
+                 AND p.deleted_at IS NULL
+                """;
+        if (after != null) {
+            sql += " AND (p.published_at, p.id) < (:cursorPublishedAt, :cursorId)";
+        }
+        sql += " ORDER BY p.published_at DESC, p.id DESC LIMIT :limit";
+        var spec = jdbcClient.sql(sql)
+                .param("viewerId", viewerId)
+                .param("limit", limitPlusOne);
+        if (after != null) {
+            spec = spec.param("cursorPublishedAt", after.publishedAt())
+                    .param("cursorId", after.id());
+        }
+        return spec.query(PostRepository::mapPost).list();
+    }
+
+    /**
+     * One my-bookmarks page in (bookmarks.created_at DESC, post_id DESC) —
+     * the exact key of ix_post_bookmarks_user_created. Bookmarked posts
+     * that turned invisible (deleted, hidden/archived, non-public) are
+     * filtered INSIDE the keyset query（草案「静默剔除」定型）: the cursor
+     * keys on the relation row, so dropped posts cost nothing to
+     * pagination correctness. The caller asks for limit+1 rows to learn
+     * whether more exist.
+     */
+    public List<BookmarkedPostRow> pageBookmarked(UUID userId, BookmarkCursor after,
+                                                  int limitPlusOne) {
+        String sql = """
+                SELECT p.id, p.author_user_id, p.pet_id, p.category, p.title, p.content,
+                       p.status, p.visibility, p.like_count, p.comment_count, p.bookmark_count,
+                       p.created_at, p.updated_at, p.published_at, p.deleted_at, p.version, p.request_hash,
+                       EXISTS (SELECT 1 FROM community.post_likes pl
+                               WHERE pl.post_id = p.id AND pl.user_id = :viewerId) AS liked_by_me,
+                       true AS bookmarked_by_me,
+                       b.created_at AS bookmarked_at
+                FROM community.post_bookmarks b
+                JOIN community.posts p ON p.id = b.post_id
+                WHERE b.user_id = :viewerId
+                AND p.status = 'published' AND p.visibility = 'public' AND p.deleted_at IS NULL
+                """;
+        if (after != null) {
+            sql += " AND (b.created_at, b.post_id) < (:cursorBookmarkedAt, :cursorPostId)";
+        }
+        sql += " ORDER BY b.created_at DESC, b.post_id DESC LIMIT :limit";
+        var spec = jdbcClient.sql(sql)
+                .param("viewerId", userId)
+                .param("limit", limitPlusOne);
+        if (after != null) {
+            spec = spec.param("cursorBookmarkedAt", after.bookmarkedAt())
+                    .param("cursorPostId", after.postId());
+        }
+        return spec.query((rs, rowNum) -> new BookmarkedPostRow(
+                mapPost(rs, rowNum),
+                rs.getObject("bookmarked_at", OffsetDateTime.class))).list();
+    }
+
     public void insertMedia(UUID postId, int position, UUID assetId, boolean isCover, String caption) {
         jdbcClient.sql("""
                         INSERT INTO community.post_media (post_id, position, asset_id, is_cover, caption)
@@ -321,4 +391,8 @@ public class PostRepository {
             Integer widthPx,
             Integer heightPx) {
     }
+
+    /** A bookmarked post plus the relation row's timestamp (the page key). */
+    public record BookmarkedPostRow(PostRow post, OffsetDateTime bookmarkedAt) {
+    }
 }

patbond-community/src/main/java/com/patbond/patbond/community/service/CommentService.java

@@ -0,0 +1,177 @@
+package com.patbond.patbond.community.service;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+import com.patbond.patbond.community.access.UserExistenceGateway;
+import com.patbond.patbond.community.author.AuthorProfileGateway;
+import com.patbond.patbond.community.dto.AuthorSummaryResponse;
+import com.patbond.patbond.community.dto.CommentResponse;
+import com.patbond.patbond.community.dto.CreateCommentRequest;
+import com.patbond.patbond.community.dto.CursorPage;
+import com.patbond.patbond.community.repository.CommentRepository;
+import com.patbond.patbond.community.repository.CommentRepository.CommentRow;
+import com.patbond.patbond.community.repository.InteractionRepository;
+import com.patbond.patbond.community.support.CommentCursor;
+import com.patbond.patbond.community.support.RequestHashes;
+import com.patbond.patbond.community.support.UuidV7;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * Flat comments (T3-07 定型). The semantics fixed here are T3-10 freeze
+ * input:
+ *
+ * <ul>
+ *   <li><b>Interaction surface</b> — comments attach to the PUBLIC face of
+ *       a post only: published and live. A draft (its author included),
+ *       hidden/archived or soft-deleted post answers the byte-identical
+ *       404/40403 on every comment path — 互动域不区分「作者的草稿」.</li>
+ *   <li><b>Idempotent create (ADR-019)</b> — Idempotency-Key mandatory,
+ *       stored as client_request_id next to the normalized request hash;
+ *       same key + same payload returns the first comment (201 again),
+ *       different payload 40905, keys scoped per author. A replay hitting
+ *       a since-deleted first comment answers 404/40404 (T3-04 §2.4
+ *       同一先例).</li>
+ *   <li><b>Delete</b> — the comment's author only（D3-7 拍板：帖主删他人
+ *       评论首版不做）; a non-author on a visible comment gets 403/40301,
+ *       everything invisible (absent, deleted, its post invisible) merges
+ *       into 404/40404. comment_count moves -1 in the same transaction,
+ *       exactly once — the FOR UPDATE lock serializes double deletes.</li>
+ * </ul>
+ */
+@Service
+public class CommentService {
+
+    private final CommentRepository commentRepository;
+    private final InteractionRepository interactionRepository;
+    private final UserExistenceGateway userExistenceGateway;
+    private final AuthorProfileGateway authorProfileGateway;
+
+    public CommentService(CommentRepository commentRepository,
+                          InteractionRepository interactionRepository,
+                          UserExistenceGateway userExistenceGateway,
+                          AuthorProfileGateway authorProfileGateway) {
+        this.commentRepository = commentRepository;
+        this.interactionRepository = interactionRepository;
+        this.userExistenceGateway = userExistenceGateway;
+        this.authorProfileGateway = authorProfileGateway;
+    }
+
+    @Transactional(readOnly = true)
+    public CursorPage<CommentResponse> list(UUID postId, int limit, String cursor) {
+        requireInteractable(postId);
+        CommentCursor after = cursor == null ? null : CommentCursor.decode(cursor);
+        List<CommentRow> rows = commentRepository.pageByPost(postId, after, limit + 1);
+        boolean hasMore = rows.size() > limit;
+        List<CommentRow> page = hasMore ? rows.subList(0, limit) : rows;
+        String nextCursor = hasMore
+                ? new CommentCursor(page.get(limit - 1).createdAt(), page.get(limit - 1).id()).encode()
+                : null;
+        return new CursorPage<>(assemble(page), nextCursor, hasMore);
+    }
+
+    @Transactional
+    public CommentResponse create(UUID userId, UUID postId, String idempotencyKey,
+                                  CreateCommentRequest request) {
+        String key = normalizeIdempotencyKey(idempotencyKey);
+        String content = requireContent(request.getContent());
+        requireInteractable(postId);
+        if (request.getReplyToUserId() != null
+                && !userExistenceGateway.existsActive(request.getReplyToUserId())) {
+            throw new BusinessException(ErrorCode.TARGET_USER_NOT_FOUND);
+        }
+
+        byte[] requestHash = RequestHashes.sha256(
+                canonicalize(postId, content, request.getReplyToUserId()));
+        UUID id = UuidV7.generate();
+        int inserted = commentRepository.insertComment(id, postId, userId,
+                request.getReplyToUserId(), content, key, requestHash);
+        if (inserted == 0) {
+            CommentRow first = commentRepository.findByAuthorAndClientRequestId(userId, key)
+                    .orElseThrow(() -> new BusinessException(ErrorCode.INTERNAL_ERROR));
+            if (!Arrays.equals(first.requestHash(), requestHash)) {
+                throw new BusinessException(ErrorCode.IDEMPOTENCY_PAYLOAD_MISMATCH);
+            }
+            if (first.deletedAt() != null) {
+                throw new BusinessException(ErrorCode.COMMENT_NOT_FOUND);
+            }
+            return assemble(List.of(first)).get(0);
+        }
+        interactionRepository.bumpCommentCount(postId, 1);
+        CommentRow row = commentRepository.lockVisibleById(id)
+                .orElseThrow(() -> new BusinessException(ErrorCode.INTERNAL_ERROR));
+        return assemble(List.of(row)).get(0);
+    }
+
+    @Transactional
+    public void delete(UUID userId, UUID commentId) {
+        CommentRow comment = commentRepository.lockVisibleById(commentId)
+                .orElseThrow(() -> new BusinessException(ErrorCode.COMMENT_NOT_FOUND));
+        if (!interactionRepository.isInteractable(comment.postId())) {
+            throw new BusinessException(ErrorCode.COMMENT_NOT_FOUND);
+        }
+        if (!comment.authorUserId().equals(userId)) {
+            throw new BusinessException(ErrorCode.POST_ACCESS_DENIED);
+        }
+        commentRepository.softDelete(commentId);
+        interactionRepository.bumpCommentCount(comment.postId(), -1);
+    }
+
+    private void requireInteractable(UUID postId) {
+        if (!interactionRepository.isInteractable(postId)) {
+            throw new BusinessException(ErrorCode.POST_NOT_FOUND);
+        }
+    }
+
+    private static String normalizeIdempotencyKey(String idempotencyKey) {
+        String key = idempotencyKey == null ? "" : idempotencyKey.trim();
+        if (key.isEmpty() || key.length() > 128) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR,
+                    "Idempotency-Key 必带且长度须在 1~128 字符");
+        }
+        return key;
+    }
+
+    private static String requireContent(String content) {
+        String trimmed = content == null ? "" : content.trim();
+        if (trimmed.isEmpty() || trimmed.length() > 2000) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR, "content 长度须在 1~2000 字符");
+        }
+        return trimmed;
+    }
+
+    /** Canonical form fed to the request hash — see {@link RequestHashes}. */
+    private static String canonicalize(UUID postId, String content, UUID replyToUserId) {
+        return "comment.v1\n" + postId + '\n'
+                + (replyToUserId == null ? "" : replyToUserId) + '\n'
+                + content + '\n';
+    }
+
+    private List<CommentResponse> assemble(List<CommentRow> rows) {
+        Set<UUID> userIds = new HashSet<>();
+        for (CommentRow row : rows) {
+            userIds.add(row.authorUserId());
+            if (row.replyToUserId() != null) {
+                userIds.add(row.replyToUserId());
+            }
+        }
+        Map<UUID, AuthorSummaryResponse> profiles = authorProfileGateway.summarize(userIds);
+        return rows.stream().map(row -> new CommentResponse(
+                row.id(),
+                row.postId(),
+                profiles.getOrDefault(row.authorUserId(),
+                        AuthorSummaryResponse.idOnly(row.authorUserId())),
+                row.replyToUserId() == null ? null
+                        : profiles.getOrDefault(row.replyToUserId(),
+                                AuthorSummaryResponse.idOnly(row.replyToUserId())),
+                row.content(),
+                row.createdAt())).toList();
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/service/FeedService.java

@@ -0,0 +1,142 @@
+package com.patbond.patbond.community.service;
+
+import com.patbond.patbond.community.author.AuthorProfileGateway;
+import com.patbond.patbond.community.dto.AuthorSummaryResponse;
+import com.patbond.patbond.community.dto.CursorPage;
+import com.patbond.patbond.community.dto.FeedCardResponse;
+import com.patbond.patbond.community.dto.PostMediaItemResponse;
+import com.patbond.patbond.community.media.MediaUrlSigner;
+import com.patbond.patbond.community.repository.PostRepository;
+import com.patbond.patbond.community.repository.PostRepository.BookmarkedPostRow;
+import com.patbond.patbond.community.repository.PostRepository.PostMediaRow;
+import com.patbond.patbond.community.repository.PostRepository.PostRow;
+import com.patbond.patbond.community.support.BookmarkCursor;
+import com.patbond.patbond.community.support.FeedCursor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+/**
+ * The public feed (T3-05): keyset pagination over the ix_posts_feed key
+ * (published_at DESC, id DESC), cards assembled from the posts row (counts
+ * come from the denormalized like/comment/bookmark_count columns — the
+ * writers of T3-06/T3-07 maintain them in the same transaction as the
+ * relation rows), the cover media item, the viewer's liked/bookmarked flags
+ * and the D3-9 author summary. Everything is batch: one page query, one
+ * media query, at most one profile call — no per-card work.
+ */
+@Service
+public class FeedService {
+
+    /** Frozen preview rule: the first 200 Unicode code points, verbatim. */
+    static final int PREVIEW_CODE_POINTS = 200;
+
+    private final PostRepository postRepository;
+    private final MediaUrlSigner mediaUrlSigner;
+    private final AuthorProfileGateway authorProfileGateway;
+
+    public FeedService(PostRepository postRepository, MediaUrlSigner mediaUrlSigner,
+                       AuthorProfileGateway authorProfileGateway) {
+        this.postRepository = postRepository;
+        this.mediaUrlSigner = mediaUrlSigner;
+        this.authorProfileGateway = authorProfileGateway;
+    }
+
+    @Transactional(readOnly = true)
+    public CursorPage<FeedCardResponse> list(UUID viewerId, int limit, String cursor) {
+        FeedCursor after = cursor == null ? null : FeedCursor.decode(cursor);
+        List<PostRow> rows = postRepository.pageFeed(viewerId, after, limit + 1);
+        boolean hasMore = rows.size() > limit;
+        List<PostRow> page = hasMore ? rows.subList(0, limit) : rows;
+        String nextCursor = hasMore
+                ? new FeedCursor(page.get(limit - 1).publishedAt(), page.get(limit - 1).id()).encode()
+                : null;
+        return new CursorPage<>(assembleCards(page), nextCursor, hasMore);
+    }
+
+    /**
+     * My-bookmarks page (T3-07): the item IS the feed card（草案定型：项
+     * 形态复用 Feed 卡片）, the order and cursor key on the bookmark
+     * relation row, and posts that turned invisible since bookmarking are
+     * silently dropped inside the page query — the same public-face
+     * predicate the feed uses, so a card here never breaks the
+     * publishedAt-non-null invariant.
+     */
+    @Transactional(readOnly = true)
+    public CursorPage<FeedCardResponse> listBookmarked(UUID userId, int limit, String cursor) {
+        BookmarkCursor after = cursor == null ? null : BookmarkCursor.decode(cursor);
+        List<BookmarkedPostRow> rows = postRepository.pageBookmarked(userId, after, limit + 1);
+        boolean hasMore = rows.size() > limit;
+        List<BookmarkedPostRow> page = hasMore ? rows.subList(0, limit) : rows;
+        String nextCursor = hasMore
+                ? new BookmarkCursor(page.get(limit - 1).bookmarkedAt(),
+                        page.get(limit - 1).post().id()).encode()
+                : null;
+        return new CursorPage<>(assembleCards(page.stream().map(BookmarkedPostRow::post).toList()),
+                nextCursor, hasMore);
+    }
+
+    private List<FeedCardResponse> assembleCards(List<PostRow> rows) {
+        Map<UUID, List<PostMediaRow>> mediaByPost = postRepository
+                .findMediaByPostIds(rows.stream().map(PostRow::id).toList())
+                .stream()
+                .collect(Collectors.groupingBy(PostMediaRow::postId));
+        Map<UUID, AuthorSummaryResponse> authors = authorProfileGateway.summarize(
+                rows.stream().map(PostRow::authorUserId).collect(Collectors.toSet()));
+        return rows.stream().map(row -> {
+            List<PostMediaRow> media = mediaByPost.getOrDefault(row.id(), List.of());
+            return new FeedCardResponse(
+                    row.id(),
+                    authors.getOrDefault(row.authorUserId(),
+                            AuthorSummaryResponse.idOnly(row.authorUserId())),
+                    row.category(),
+                    row.title(),
+                    preview(row.content()),
+                    coverOf(media),
+                    media.size(),
+                    row.likeCount(),
+                    row.commentCount(),
+                    row.bookmarkCount(),
+                    row.likedByMe(),
+                    row.bookmarkedByMe(),
+                    row.publishedAt());
+        }).toList();
+    }
+
+    /**
+     * The is_cover row (unique per post, and present whenever media exist —
+     * T3-04 §2.6 sets it on position 0 when the author picked none).
+     */
+    private PostMediaItemResponse coverOf(List<PostMediaRow> media) {
+        return media.stream()
+                .filter(PostMediaRow::isCover)
+                .findFirst()
+                .map(m -> new PostMediaItemResponse(
+                        m.assetId(),
+                        m.position(),
+                        m.isCover(),
+                        mediaUrlSigner.signGet(m.bucket(), m.objectKey()),
+                        m.widthPx(),
+                        m.heightPx(),
+                        m.caption()))
+                .orElse(null);
+    }
+
+    /**
+     * Preview = the first {@value #PREVIEW_CODE_POINTS} code points of the
+     * stored content, cut on a code-point boundary (no surrogate is ever
+     * split), no ellipsis appended — whether the card is a truncation is
+     * the client's call via {@code contentPreview.length} vs its own
+     * rendering, and the full text always comes from the detail endpoint.
+     */
+    static String preview(String content) {
+        if (content.codePointCount(0, content.length()) <= PREVIEW_CODE_POINTS) {
+            return content;
+        }
+        return content.substring(0, content.offsetByCodePoints(0, PREVIEW_CODE_POINTS));
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/service/FollowService.java

@@ -0,0 +1,67 @@
+package com.patbond.patbond.community.service;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+import com.patbond.patbond.community.access.UserExistenceGateway;
+import com.patbond.patbond.community.dto.FollowStateResponse;
+import com.patbond.patbond.community.dto.FollowStatsResponse;
+import com.patbond.patbond.community.repository.InteractionRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.UUID;
+
+/**
+ * The ADR-018 minimal follow surface: follow/unfollow (PUT/DELETE
+ * idempotent on the composite primary key, ADR-019) plus the follow-stats
+ * numbers. Counts are real-time COUNTs — user_follows carries no
+ * denormalized counters, and both directions ride an index. The target
+ * must be an existing active user (404/40406, absent and 注销 merged);
+ * following oneself is 422/42204 on PUT (ck_user_follows_self is the
+ * database backstop), while DELETE stays a plain idempotent no-op — a
+ * self-follow row cannot exist, so the authoritative false is the truth.
+ */
+@Service
+public class FollowService {
+
+    private final InteractionRepository interactionRepository;
+    private final UserExistenceGateway userExistenceGateway;
+
+    public FollowService(InteractionRepository interactionRepository,
+                         UserExistenceGateway userExistenceGateway) {
+        this.interactionRepository = interactionRepository;
+        this.userExistenceGateway = userExistenceGateway;
+    }
+
+    @Transactional
+    public FollowStateResponse follow(UUID userId, UUID targetUserId) {
+        if (userId.equals(targetUserId)) {
+            throw new BusinessException(ErrorCode.FOLLOW_RULE_VIOLATION);
+        }
+        requireActive(targetUserId);
+        interactionRepository.insertFollow(userId, targetUserId);
+        return new FollowStateResponse(true, interactionRepository.countFollowers(targetUserId));
+    }
+
+    @Transactional
+    public FollowStateResponse unfollow(UUID userId, UUID targetUserId) {
+        requireActive(targetUserId);
+        interactionRepository.deleteFollow(userId, targetUserId);
+        return new FollowStateResponse(false, interactionRepository.countFollowers(targetUserId));
+    }
+
+    @Transactional(readOnly = true)
+    public FollowStatsResponse stats(UUID viewerId, UUID targetUserId) {
+        requireActive(targetUserId);
+        return new FollowStatsResponse(
+                interactionRepository.countFollowers(targetUserId),
+                interactionRepository.countFollowing(targetUserId),
+                interactionRepository.followExists(viewerId, targetUserId));
+    }
+
+    private void requireActive(UUID targetUserId) {
+        if (!userExistenceGateway.existsActive(targetUserId)) {
+            throw new BusinessException(ErrorCode.TARGET_USER_NOT_FOUND);
+        }
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/service/InteractionService.java

@@ -0,0 +1,78 @@
+package com.patbond.patbond.community.service;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+import com.patbond.patbond.community.dto.BookmarkStateResponse;
+import com.patbond.patbond.community.dto.LikeStateResponse;
+import com.patbond.patbond.community.repository.InteractionRepository;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.UUID;
+
+/**
+ * Binary post interactions (T3-06, ADR-019): PUT/DELETE are idempotent by
+ * construction — the relation row's composite primary key is the
+ * idempotency key, the counter column moves in the same transaction and
+ * only by the number of rows the relation write actually changed, so
+ * concurrent duplicates converge (N concurrent PUTs land exactly one row
+ * and exactly +1) and every response carries the authoritative terminal
+ * state. The interaction gate is the post's public face: anything not
+ * published-and-live answers the byte-identical 404/40403 on PUT and
+ * DELETE alike.
+ */
+@Service
+public class InteractionService {
+
+    private final InteractionRepository interactionRepository;
+
+    public InteractionService(InteractionRepository interactionRepository) {
+        this.interactionRepository = interactionRepository;
+    }
+
+    @Transactional
+    public LikeStateResponse like(UUID userId, UUID postId) {
+        requireInteractable(postId);
+        int inserted = interactionRepository.insertLike(postId, userId);
+        long count = inserted > 0
+                ? interactionRepository.bumpLikeCount(postId, inserted)
+                : interactionRepository.likeCount(postId);
+        return new LikeStateResponse(true, count);
+    }
+
+    @Transactional
+    public LikeStateResponse unlike(UUID userId, UUID postId) {
+        requireInteractable(postId);
+        int deleted = interactionRepository.deleteLike(postId, userId);
+        long count = deleted > 0
+                ? interactionRepository.bumpLikeCount(postId, -deleted)
+                : interactionRepository.likeCount(postId);
+        return new LikeStateResponse(false, count);
+    }
+
+    @Transactional
+    public BookmarkStateResponse bookmark(UUID userId, UUID postId) {
+        requireInteractable(postId);
+        int inserted = interactionRepository.insertBookmark(postId, userId);
+        long count = inserted > 0
+                ? interactionRepository.bumpBookmarkCount(postId, inserted)
+                : interactionRepository.bookmarkCount(postId);
+        return new BookmarkStateResponse(true, count);
+    }
+
+    @Transactional
+    public BookmarkStateResponse unbookmark(UUID userId, UUID postId) {
+        requireInteractable(postId);
+        int deleted = interactionRepository.deleteBookmark(postId, userId);
+        long count = deleted > 0
+                ? interactionRepository.bumpBookmarkCount(postId, -deleted)
+                : interactionRepository.bookmarkCount(postId);
+        return new BookmarkStateResponse(false, count);
+    }
+
+    private void requireInteractable(UUID postId) {
+        if (!interactionRepository.isInteractable(postId)) {
+            throw new BusinessException(ErrorCode.POST_NOT_FOUND);
+        }
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/service/PostService.java

@@ -3,6 +3,8 @@ package com.patbond.patbond.community.service;
 import com.patbond.patbond.common.error.BusinessException;
 import com.patbond.patbond.common.error.ErrorCode;
 import com.patbond.patbond.community.access.PetVisibilityGateway;
+import com.patbond.patbond.community.author.AuthorProfileGateway;
+import com.patbond.patbond.community.dto.AuthorSummaryResponse;
 import com.patbond.patbond.community.dto.CreatePostRequest;
 import com.patbond.patbond.community.dto.CursorPage;
 import com.patbond.patbond.community.dto.PostMediaAttachRequest;
@@ -65,13 +67,16 @@ public class PostService {
     private final MediaAssetGateway mediaAssetGateway;
     private final MediaUrlSigner mediaUrlSigner;
     private final PetVisibilityGateway petVisibilityGateway;
+    private final AuthorProfileGateway authorProfileGateway;
 
     public PostService(PostRepository postRepository, MediaAssetGateway mediaAssetGateway,
-                       MediaUrlSigner mediaUrlSigner, PetVisibilityGateway petVisibilityGateway) {
+                       MediaUrlSigner mediaUrlSigner, PetVisibilityGateway petVisibilityGateway,
+                       AuthorProfileGateway authorProfileGateway) {
         this.postRepository = postRepository;
         this.mediaAssetGateway = mediaAssetGateway;
         this.mediaUrlSigner = mediaUrlSigner;
         this.petVisibilityGateway = petVisibilityGateway;
+        this.authorProfileGateway = authorProfileGateway;
     }
 
     @Transactional
@@ -374,9 +379,12 @@ public class PostService {
                 .findMediaByPostIds(rows.stream().map(PostRow::id).toList())
                 .stream()
                 .collect(Collectors.groupingBy(PostMediaRow::postId));
+        Map<UUID, AuthorSummaryResponse> authors = authorProfileGateway.summarize(
+                rows.stream().map(PostRow::authorUserId).collect(Collectors.toSet()));
         return rows.stream().map(row -> new PostResponse(
                 row.id(),
-                row.authorUserId(),
+                authors.getOrDefault(row.authorUserId(),
+                        AuthorSummaryResponse.idOnly(row.authorUserId())),
                 row.petId(),
                 row.category(),
                 row.title(),

patbond-community/src/main/java/com/patbond/patbond/community/support/BookmarkCursor.java

@@ -0,0 +1,46 @@
+package com.patbond.patbond.community.support;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.util.Base64;
+import java.util.UUID;
+
+/**
+ * Opaque cursor of the my-bookmarks list (bookmarks.created_at DESC,
+ * post_id DESC — the exact key of ix_post_bookmarks_user_created). The key
+ * lives on the RELATION row, not the post: a bookmarked post that later
+ * turns invisible is filtered inside the same keyset query, so pages stay
+ * complete and the cursor never points at a value the client saw filtered.
+ * Encoding is the shared base64url("epochMicros:id") shape.
+ */
+public record BookmarkCursor(OffsetDateTime bookmarkedAt, UUID postId) {
+
+    public String encode() {
+        long micros = Math.multiplyExact(bookmarkedAt.toInstant().getEpochSecond(), 1_000_000L)
+                + bookmarkedAt.getNano() / 1_000L;
+        return Base64.getUrlEncoder().withoutPadding()
+                .encodeToString((micros + ":" + postId).getBytes(StandardCharsets.UTF_8));
+    }
+
+    /** @throws BusinessException 40000 when the cursor is not one we issued */
+    public static BookmarkCursor decode(String cursor) {
+        try {
+            String raw = new String(Base64.getUrlDecoder().decode(cursor), StandardCharsets.UTF_8);
+            int sep = raw.indexOf(':');
+            long micros = Long.parseLong(raw.substring(0, sep));
+            UUID postId = UUID.fromString(raw.substring(sep + 1));
+            OffsetDateTime bookmarkedAt = Instant.ofEpochSecond(
+                            Math.floorDiv(micros, 1_000_000L),
+                            Math.floorMod(micros, 1_000_000L) * 1_000L)
+                    .atOffset(ZoneOffset.UTC);
+            return new BookmarkCursor(bookmarkedAt, postId);
+        } catch (RuntimeException e) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR, "cursor 无效");
+        }
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/support/CommentCursor.java

@@ -0,0 +1,45 @@
+package com.patbond.patbond.community.support;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.util.Base64;
+import java.util.UUID;
+
+/**
+ * Opaque cursor of a post's comment list (created_at DESC, id DESC — the
+ * exact key of ix_comments_post_created), same encoding as
+ * {@link PostCursor}: base64url("epochMicros:id"), next page selects
+ * {@code (created_at, id) < (cursor)} so ties on created_at are broken by
+ * id and rows are neither lost nor repeated across page boundaries.
+ */
+public record CommentCursor(OffsetDateTime createdAt, UUID id) {
+
+    public String encode() {
+        long micros = Math.multiplyExact(createdAt.toInstant().getEpochSecond(), 1_000_000L)
+                + createdAt.getNano() / 1_000L;
+        return Base64.getUrlEncoder().withoutPadding()
+                .encodeToString((micros + ":" + id).getBytes(StandardCharsets.UTF_8));
+    }
+
+    /** @throws BusinessException 40000 when the cursor is not one we issued */
+    public static CommentCursor decode(String cursor) {
+        try {
+            String raw = new String(Base64.getUrlDecoder().decode(cursor), StandardCharsets.UTF_8);
+            int sep = raw.indexOf(':');
+            long micros = Long.parseLong(raw.substring(0, sep));
+            UUID id = UUID.fromString(raw.substring(sep + 1));
+            OffsetDateTime createdAt = Instant.ofEpochSecond(
+                            Math.floorDiv(micros, 1_000_000L),
+                            Math.floorMod(micros, 1_000_000L) * 1_000L)
+                    .atOffset(ZoneOffset.UTC);
+            return new CommentCursor(createdAt, id);
+        } catch (RuntimeException e) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR, "cursor 无效");
+        }
+    }
+}

patbond-community/src/main/java/com/patbond/patbond/community/support/FeedCursor.java

@@ -0,0 +1,46 @@
+package com.patbond.patbond.community.support;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.util.Base64;
+import java.util.UUID;
+
+/**
+ * Opaque cursor of the public feed (published_at DESC, id DESC — the exact
+ * key of ix_posts_feed), same encoding as {@link PostCursor}:
+ * base64url("epochMicros:id"), next page selects
+ * {@code (published_at, id) < (cursor)} so ties on published_at are broken
+ * by id and rows are neither lost nor repeated across page boundaries.
+ * timestamptz carries microseconds, so the micros encoding is lossless.
+ */
+public record FeedCursor(OffsetDateTime publishedAt, UUID id) {
+
+    public String encode() {
+        long micros = Math.multiplyExact(publishedAt.toInstant().getEpochSecond(), 1_000_000L)
+                + publishedAt.getNano() / 1_000L;
+        return Base64.getUrlEncoder().withoutPadding()
+                .encodeToString((micros + ":" + id).getBytes(StandardCharsets.UTF_8));
+    }
+
+    /** @throws BusinessException 40000 when the cursor is not one we issued */
+    public static FeedCursor decode(String cursor) {
+        try {
+            String raw = new String(Base64.getUrlDecoder().decode(cursor), StandardCharsets.UTF_8);
+            int sep = raw.indexOf(':');
+            long micros = Long.parseLong(raw.substring(0, sep));
+            UUID id = UUID.fromString(raw.substring(sep + 1));
+            OffsetDateTime publishedAt = Instant.ofEpochSecond(
+                            Math.floorDiv(micros, 1_000_000L),
+                            Math.floorMod(micros, 1_000_000L) * 1_000L)
+                    .atOffset(ZoneOffset.UTC);
+            return new FeedCursor(publishedAt, id);
+        } catch (RuntimeException e) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR, "cursor 无效");
+        }
+    }
+}

patbond-community/src/main/resources/application.yml.sample

@@ -20,6 +20,16 @@ patbond:
     # 值可以是 PEM 文件路径，也可以是内联 PEM 内容（以 -----BEGIN 开头）。
     # 私钥只给 patbond-auth，绝不入库。
     public-key: ${PATBOND_JWT_PUBLIC_KEY:}
+  # 作者公开资料来源（D3-9 方案 B）：patbond-user 的 /internal 批量接口，
+  # ADR-002 静态直连。不可达时 Feed/详情照常返回，作者摘要降级为仅 userId。
+  user-service:
+    url: ${PATBOND_USER_SERVICE_URL:http://127.0.0.1:8082}
+  # /internal/** 服务间共享密钥，需与 patbond-user 配置同一值；生产环境必须
+  # 通过 PATBOND_INTERNAL_TOKEN 注入强随机值（如 `openssl rand -hex 32`）。
+  internal-token: ${PATBOND_INTERNAL_TOKEN:dev-only-internal-token}
+  author-profile:
+    # 作者公开资料的进程内缓存 TTL：昵称/头像变更最迟一分钟可见。
+    cache-ttl: ${PATBOND_AUTHOR_PROFILE_CACHE_TTL:60s}
   media:
     # 媒体读取侧（ADR-016 定型：私有桶 + 预签名 GET）。本服务只做本地 SigV4
     # 签名计算生成图片访问 URL，从不直连对象存储；写入流程在 patbond-user。

patbond-community/src/test/java/com/patbond/patbond/community/author/AuthorProfileClientWireTest.java

@@ -0,0 +1,146 @@
+package com.patbond.patbond.community.author;
+
+import com.patbond.patbond.community.TestcontainersConfiguration;
+import com.patbond.patbond.community.dto.AuthorSummaryResponse;
+import com.patbond.patbond.community.support.CommunityTestData;
+import com.patbond.patbond.community.support.TestJwtKeys;
+import com.sun.net.httpserver.HttpServer;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.test.context.DynamicPropertyRegistry;
+import org.springframework.test.context.DynamicPropertySource;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.InetSocketAddress;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * The real Feign wiring against an in-test HTTP server standing in for
+ * patbond-user: static URL resolution, the X-Internal-Token interceptor,
+ * query-string batching, envelope decoding, avatar resolution through
+ * media.assets plus URL signing — and degradation when the downstream
+ * answers an error. (The /internal endpoint itself is tested in the
+ * patbond-user module; the DB-backed stub covers the service-level tests.)
+ */
+@SpringBootTest
+@Import(TestcontainersConfiguration.class)
+class AuthorProfileClientWireTest {
+
+    private static final HttpServer SERVER;
+    private static final AtomicReference<String> RESPONSE_BODY = new AtomicReference<>("");
+    private static final AtomicInteger RESPONSE_STATUS = new AtomicInteger(200);
+    private static final AtomicReference<String> SEEN_TOKEN = new AtomicReference<>();
+    private static final AtomicReference<String> SEEN_QUERY = new AtomicReference<>();
+
+    static {
+        try {
+            SERVER = HttpServer.create(new InetSocketAddress("127.0.0.1", 0), 0);
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        SERVER.createContext("/internal/users/profiles", exchange -> {
+            SEEN_TOKEN.set(exchange.getRequestHeaders().getFirst("X-Internal-Token"));
+            SEEN_QUERY.set(exchange.getRequestURI().getRawQuery());
+            byte[] body = RESPONSE_BODY.get().getBytes(StandardCharsets.UTF_8);
+            exchange.getResponseHeaders().set("Content-Type", "application/json");
+            exchange.sendResponseHeaders(RESPONSE_STATUS.get(), body.length);
+            try (OutputStream out = exchange.getResponseBody()) {
+                out.write(body);
+            }
+        });
+        SERVER.start();
+    }
+
+    @DynamicPropertySource
+    static void properties(DynamicPropertyRegistry registry) {
+        registry.add("patbond.jwt.public-key", TestJwtKeys::publicPem);
+        registry.add("patbond.user-service.url",
+                () -> "http://127.0.0.1:" + SERVER.getAddress().getPort());
+        registry.add("patbond.media.public-endpoint", () -> "http://127.0.0.1:9000");
+        registry.add("patbond.media.access-key", () -> "test-access-key");
+        registry.add("patbond.media.secret-key", () -> "test-secret-key");
+    }
+
+    @AfterAll
+    static void stopServer() {
+        SERVER.stop(0);
+    }
+
+    @Autowired
+    private AuthorProfileGateway gateway;
+
+    @Autowired
+    private JdbcClient jdbcClient;
+
+    @BeforeEach
+    void resetServer() {
+        RESPONSE_STATUS.set(200);
+        RESPONSE_BODY.set("{\"code\":0,\"message\":\"success\",\"data\":[]}");
+        SEEN_TOKEN.set(null);
+        SEEN_QUERY.set(null);
+    }
+
+    private UUID newUser() {
+        return CommunityTestData.insertUser(jdbcClient,
+                "w" + Long.toHexString(ThreadLocalRandom.current().nextLong() & 0x7FFFFFFFFFFFFFFFL));
+    }
+
+    @Test
+    void presentsTheServiceSecretAndBatchesIdsIntoOneQuery() {
+        UUID userA = UUID.randomUUID();
+        UUID userB = UUID.randomUUID();
+        RESPONSE_BODY.set("""
+                {"code":0,"message":"success","data":[
+                  {"userId":"%s","nickname":"小白","avatarAssetId":null}
+                ]}""".formatted(userA));
+
+        Map<UUID, AuthorSummaryResponse> summaries =
+                gateway.summarize(java.util.List.of(userA, userB));
+
+        assertThat(SEEN_TOKEN.get()).isEqualTo("test-internal-token");
+        String ids = URLDecoder.decode(SEEN_QUERY.get(), StandardCharsets.UTF_8)
+                .replaceFirst("^ids=", "");
+        assertThat(ids.split(",")).containsExactlyInAnyOrder(
+                userA.toString(), userB.toString());
+        assertThat(summaries).containsOnlyKeys(userA);
+        assertThat(summaries.get(userA).nickname()).isEqualTo("小白");
+        assertThat(summaries.get(userA).avatarUrl()).isNull();
+    }
+
+    @Test
+    void resolvesTheAvatarAssetLocallyAndSignsTheUrl() {
+        UUID owner = newUser();
+        UUID assetId = CommunityTestData.insertReadyAsset(jdbcClient, owner);
+        RESPONSE_BODY.set("""
+                {"code":0,"message":"success","data":[
+                  {"userId":"%s","nickname":"有头像","avatarAssetId":"%s"}
+                ]}""".formatted(owner, assetId));
+
+        AuthorSummaryResponse summary = gateway.summarize(java.util.List.of(owner)).get(owner);
+        assertThat(summary.nickname()).isEqualTo("有头像");
+        assertThat(summary.avatarUrl())
+                .contains(assetId.toString())
+                .contains("X-Amz-Signature");
+    }
+
+    @Test
+    void aDownstreamErrorDegradesToNoSummaries() {
+        RESPONSE_STATUS.set(500);
+        RESPONSE_BODY.set("{\"code\":50000,\"message\":\"boom\",\"data\":null}");
+        assertThat(gateway.summarize(java.util.List.of(UUID.randomUUID()))).isEmpty();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/contract/CommunityContractConformanceTest.java

@@ -0,0 +1,512 @@
+package com.patbond.patbond.community.contract;
+
+import com.jayway.jsonpath.JsonPath;
+import com.patbond.patbond.community.post.PostApiTestBase;
+import com.patbond.patbond.community.support.CommunityTestData;
+import org.junit.jupiter.api.MethodOrderer;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestMethodOrder;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
+
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.patch;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.request;
+
+/**
+ * T3-20（M3 第二波收尾）：community 域 17 个操作补进契约一致性保障，机制与
+ * patbond-pet 的 ContractConformanceTest 同构——对冻结契约 v1.3.0（快照
+ * {@code src/test/resources/contract/openapi-v1.3.0.yaml}，正典在 doc 仓
+ * {@code docs/api/openapi.yaml}）逐操作真实起服务发请求，用
+ * {@link ContractValidator} 严格校验响应结构：路径/方法/状态码已声明、字段名
+ * 与类型、必填与 nullable、枚举与格式、信封结构、错误码值。
+ *
+ * <p>覆盖目标是**全响应矩阵**：最后的 {@link #everyDeclaredResponseCellIsExercised()}
+ * 断言契约为这 17 个操作声明的每一个 (操作, 状态码) 单元格（共 64 格）都被
+ * 至少一次真实响应校验过，**无豁免**——community 域的 409 均为幂等键/乐观锁
+ * 冲突、422 均为业务规则拒绝，单线程即可确定性触发。
+ *
+ * <p>media 域 2 个操作属 patbond-user 模块，由该模块的
+ * MediaContractConformanceTest 覆盖（快照同一份）。
+ */
+@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
+class CommunityContractConformanceTest extends PostApiTestBase {
+
+    private static final OpenApiContract CONTRACT = OpenApiContract.load();
+    private static final ContractValidator VALIDATOR = new ContractValidator(CONTRACT);
+
+    /** 已被真实响应校验过的 (操作, 状态码) 单元格，如 "GET /api/v1/feed 200"。 */
+    private static final Set<String> COVERED = ConcurrentHashMap.newKeySet();
+
+    /** community 域 17 个操作（= 契约中 tags ∈ {posts, feed, comments, interactions, follows}）。 */
+    private static final List<String> COMMUNITY_OPERATIONS = List.of(
+            "POST /api/v1/posts",
+            "GET /api/v1/posts/{postId}",
+            "PATCH /api/v1/posts/{postId}",
+            "DELETE /api/v1/posts/{postId}",
+            "GET /api/v1/me/posts",
+            "GET /api/v1/feed",
+            "GET /api/v1/posts/{postId}/comments",
+            "POST /api/v1/posts/{postId}/comments",
+            "DELETE /api/v1/comments/{commentId}",
+            "PUT /api/v1/posts/{postId}/like",
+            "DELETE /api/v1/posts/{postId}/like",
+            "PUT /api/v1/posts/{postId}/bookmark",
+            "DELETE /api/v1/posts/{postId}/bookmark",
+            "GET /api/v1/me/bookmarks",
+            "PUT /api/v1/users/{userId}/follow",
+            "DELETE /api/v1/users/{userId}/follow",
+            "GET /api/v1/users/{userId}/follow-stats");
+
+    private static final String IDEMPOTENCY_KEY = "Idempotency-Key";
+
+    // ---- 校验骨架 ------------------------------------------------------
+
+    /**
+     * 执行请求，断言 HTTP 状态，并将响应体对照冻结契约严格校验；通过后把
+     * (操作, 状态码) 记入覆盖表。返回响应体供取 id/cursor。
+     */
+    private String verified(MockHttpServletRequestBuilder rq, String method,
+                            String pathTemplate, int expectedStatus) throws Exception {
+        MvcResult result = mockMvc.perform(rq).andReturn();
+        int actual = result.getResponse().getStatus();
+        String body = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
+        assertThat(actual)
+                .as("%s %s 的 HTTP 状态（响应体: %s）", method, pathTemplate, body)
+                .isEqualTo(expectedStatus);
+        List<String> drift = VALIDATOR.validateResponse(method, pathTemplate, actual, body);
+        assertThat(drift).as("%s %s %d 响应与冻结契约漂移", method, pathTemplate, actual).isEmpty();
+        COVERED.add(method + " " + pathTemplate + " " + actual);
+        return body;
+    }
+
+    /** 同上，并额外断言信封 code 等于契约错误码表约定的业务码。 */
+    private String verifiedError(MockHttpServletRequestBuilder rq, String method,
+                                 String pathTemplate, int status, int bizCode) throws Exception {
+        String body = verified(rq, method, pathTemplate, status);
+        assertThat((Integer) JsonPath.read(body, "$.code"))
+                .as("%s %s %d 的业务错误码", method, pathTemplate, status)
+                .isEqualTo(bizCode);
+        return body;
+    }
+
+    /** 经 verified 的创建（响应同样被契约校验），返回帖子 id。 */
+    private String newPost(UUID author, String body) throws Exception {
+        String created = verified(
+                createPostRequest(author, UUID.randomUUID().toString(), body),
+                "POST", "/api/v1/posts", 201);
+        return JsonPath.read(created, "$.data.id");
+    }
+
+    private String newPublishedPost(UUID author, String content) throws Exception {
+        return newPost(author, """
+                {"content":"%s","status":"published"}
+                """.formatted(content));
+    }
+
+    private String newComment(UUID author, String postId, String content) throws Exception {
+        String created = verified(
+                authed(post("/api/v1/posts/{postId}/comments", postId), author)
+                        .header(IDEMPOTENCY_KEY, UUID.randomUUID().toString())
+                        .content("{\"content\":\"%s\"}".formatted(content)),
+                "POST", "/api/v1/posts/{postId}/comments", 201);
+        return JsonPath.read(created, "$.data.id");
+    }
+
+    // ---- 成功路径：17 操作全覆盖 ---------------------------------------
+
+    @Test
+    @Order(1)
+    void postLifecycleSuccessShapes() throws Exception {
+        UUID author = newUser();
+        UUID petId = CommunityTestData.insertPetOwnedBy(jdbcClient, author);
+        UUID asset = CommunityTestData.insertReadyAsset(jdbcClient, author);
+
+        // 全字段草稿（petId + 单图封面 + caption）
+        String draftId = newPost(author, """
+                {"title":"契约帖","content":"全字段草稿正文","category":"help",
+                 "status":"draft","petId":"%s",
+                 "media":[{"assetId":"%s","position":0,"isCover":true,"caption":"封面图"}]}
+                """.formatted(petId, asset));
+
+        // 可空字段全空的纯文字直接发布形态（nullable 声明的实证）
+        newPublishedPost(author, "契约纯文字发布帖");
+
+        verified(get("/api/v1/posts/{postId}", draftId)
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/posts/{postId}", 200);
+
+        // 发布草稿（draft→published 唯一开放迁移）
+        String published = verified(authed(patch("/api/v1/posts/{postId}", draftId), author)
+                        .content("{\"version\":0,\"status\":\"published\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 200);
+        assertThat((String) JsonPath.read(published, "$.data.status")).isEqualTo("published");
+        assertThat((Object) JsonPath.read(published, "$.data.publishedAt")).isNotNull();
+
+        // 我的帖子列表：keyset 翻页两态 + status 过滤
+        String page1 = verified(get("/api/v1/me/posts").param("limit", "1")
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/me/posts", 200);
+        assertThat((Boolean) JsonPath.read(page1, "$.data.hasMore")).isTrue();
+        String cursor = JsonPath.read(page1, "$.data.nextCursor");
+        assertThat(cursor).as("hasMore=true 时 nextCursor 非空").isNotNull();
+        verified(get("/api/v1/me/posts").param("limit", "1").param("cursor", cursor)
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/me/posts", 200);
+        verified(get("/api/v1/me/posts").param("status", "draft")
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/me/posts", 200);
+
+        // 软删（VoidEnvelope）
+        String victim = newPublishedPost(author, "契约待删帖");
+        verified(authed(delete("/api/v1/posts/{postId}", victim), author),
+                "DELETE", "/api/v1/posts/{postId}", 200);
+    }
+
+    @Test
+    @Order(2)
+    void feedSuccessShapes() throws Exception {
+        UUID author = newUser();
+        UUID reader = newUser();
+        UUID asset = CommunityTestData.insertReadyAsset(jdbcClient, author);
+
+        // 有封面与纯文字两种卡片形态（coverImage 的 allOf 非空/null 两分支）
+        newPost(author, """
+                {"title":"契约图帖","content":"Feed 封面卡片","status":"published",
+                 "media":[{"assetId":"%s","isCover":true}]}
+                """.formatted(asset));
+        newPublishedPost(author, "Feed 纯文字卡片");
+
+        String page1 = verified(get("/api/v1/feed").param("limit", "1")
+                        .header("Authorization", "Bearer " + token(reader)),
+                "GET", "/api/v1/feed", 200);
+        assertThat((Boolean) JsonPath.read(page1, "$.data.hasMore")).isTrue();
+        String cursor = JsonPath.read(page1, "$.data.nextCursor");
+        verified(get("/api/v1/feed").param("cursor", cursor)
+                        .header("Authorization", "Bearer " + token(reader)),
+                "GET", "/api/v1/feed", 200);
+    }
+
+    @Test
+    @Order(3)
+    void commentSuccessShapes() throws Exception {
+        UUID author = newUser();
+        UUID commenter = newUser();
+        String postId = newPublishedPost(author, "契约评论帖");
+
+        // 普通评论与 @ 回复（replyToUser 的 allOf null/非空两分支）
+        newComment(commenter, postId, "普通评论");
+        verified(authed(post("/api/v1/posts/{postId}/comments", postId), author)
+                        .header(IDEMPOTENCY_KEY, UUID.randomUUID().toString())
+                        .content("""
+                                {"content":"@ 回复","replyToUserId":"%s"}
+                                """.formatted(commenter)),
+                "POST", "/api/v1/posts/{postId}/comments", 201);
+
+        String page1 = verified(get("/api/v1/posts/{postId}/comments", postId)
+                        .param("limit", "1")
+                        .header("Authorization", "Bearer " + token(commenter)),
+                "GET", "/api/v1/posts/{postId}/comments", 200);
+        assertThat((Boolean) JsonPath.read(page1, "$.data.hasMore")).isTrue();
+        String cursor = JsonPath.read(page1, "$.data.nextCursor");
+        verified(get("/api/v1/posts/{postId}/comments", postId)
+                        .param("cursor", cursor)
+                        .header("Authorization", "Bearer " + token(commenter)),
+                "GET", "/api/v1/posts/{postId}/comments", 200);
+
+        // 作者软删自己的评论（VoidEnvelope）
+        String commentId = newComment(commenter, postId, "待删评论");
+        verified(authed(delete("/api/v1/comments/{commentId}", commentId), commenter),
+                "DELETE", "/api/v1/comments/{commentId}", 200);
+    }
+
+    @Test
+    @Order(4)
+    void interactionSuccessShapes() throws Exception {
+        UUID author = newUser();
+        UUID actor = newUser();
+        String postA = newPublishedPost(author, "契约互动帖 A");
+        String postB = newPublishedPost(author, "契约互动帖 B");
+
+        // PUT/DELETE 权威终态（重复 PUT 同格，幂等语义顺带实证）
+        verified(authed(put("/api/v1/posts/{postId}/like", postA), actor),
+                "PUT", "/api/v1/posts/{postId}/like", 200);
+        String likedAgain = verified(authed(put("/api/v1/posts/{postId}/like", postA), actor),
+                "PUT", "/api/v1/posts/{postId}/like", 200);
+        assertThat((Boolean) JsonPath.read(likedAgain, "$.data.liked")).isTrue();
+        assertThat((Integer) JsonPath.read(likedAgain, "$.data.likeCount")).isEqualTo(1);
+        verified(authed(delete("/api/v1/posts/{postId}/like", postA), actor),
+                "DELETE", "/api/v1/posts/{postId}/like", 200);
+
+        verified(authed(put("/api/v1/posts/{postId}/bookmark", postA), actor),
+                "PUT", "/api/v1/posts/{postId}/bookmark", 200);
+        verified(authed(put("/api/v1/posts/{postId}/bookmark", postB), actor),
+                "PUT", "/api/v1/posts/{postId}/bookmark", 200);
+
+        String page1 = verified(get("/api/v1/me/bookmarks").param("limit", "1")
+                        .header("Authorization", "Bearer " + token(actor)),
+                "GET", "/api/v1/me/bookmarks", 200);
+        assertThat((Boolean) JsonPath.read(page1, "$.data.hasMore")).isTrue();
+        String cursor = JsonPath.read(page1, "$.data.nextCursor");
+        verified(get("/api/v1/me/bookmarks").param("cursor", cursor)
+                        .header("Authorization", "Bearer " + token(actor)),
+                "GET", "/api/v1/me/bookmarks", 200);
+
+        verified(authed(delete("/api/v1/posts/{postId}/bookmark", postB), actor),
+                "DELETE", "/api/v1/posts/{postId}/bookmark", 200);
+    }
+
+    @Test
+    @Order(5)
+    void followSuccessShapes() throws Exception {
+        UUID follower = newUser();
+        UUID followee = newUser();
+
+        String followed = verified(authed(put("/api/v1/users/{userId}/follow", followee), follower),
+                "PUT", "/api/v1/users/{userId}/follow", 200);
+        assertThat((Boolean) JsonPath.read(followed, "$.data.following")).isTrue();
+
+        String stats = verified(get("/api/v1/users/{userId}/follow-stats", followee)
+                        .header("Authorization", "Bearer " + token(follower)),
+                "GET", "/api/v1/users/{userId}/follow-stats", 200);
+        assertThat((Boolean) JsonPath.read(stats, "$.data.followedByMe")).isTrue();
+
+        // 查自己：followedByMe 恒 false 分支
+        verified(get("/api/v1/users/{userId}/follow-stats", follower)
+                        .header("Authorization", "Bearer " + token(follower)),
+                "GET", "/api/v1/users/{userId}/follow-stats", 200);
+
+        verified(authed(delete("/api/v1/users/{userId}/follow", followee), follower),
+                "DELETE", "/api/v1/users/{userId}/follow", 200);
+        // 取消不存在的关注：幂等 no-op 仍 200 权威 false
+        String unfollowedAgain = verified(
+                authed(delete("/api/v1/users/{userId}/follow", followee), follower),
+                "DELETE", "/api/v1/users/{userId}/follow", 200);
+        assertThat((Boolean) JsonPath.read(unfollowedAgain, "$.data.following")).isFalse();
+    }
+
+    // ---- 错误信封 ------------------------------------------------------
+
+    @Test
+    @Order(6)
+    void unauthenticatedRequestsAnswer40101OnAllOperations() throws Exception {
+        for (String op : COMMUNITY_OPERATIONS) {
+            String[] parts = op.split(" ", 2);
+            String url = parts[1].replaceAll("\\{[^}]+}", UUID.randomUUID().toString());
+            MockHttpServletRequestBuilder rq = request(HttpMethod.valueOf(parts[0]), url);
+            if (!"GET".equals(parts[0])) {
+                rq = rq.contentType(MediaType.APPLICATION_JSON).content("{}");
+            }
+            verifiedError(rq, parts[0], parts[1], 401, 40101);
+        }
+    }
+
+    @Test
+    @Order(7)
+    void validationErrorsAnswer40000() throws Exception {
+        UUID user = newUser();
+        String postId = newPublishedPost(user, "契约校验帖");
+
+        // 创建：缺 Idempotency-Key 与空 body 两种 40000
+        verifiedError(authed(post("/api/v1/posts"), user).content("{\"content\":\"无幂等键\"}"),
+                "POST", "/api/v1/posts", 400, 40000);
+        verifiedError(createPostRequest(user, UUID.randomUUID().toString(), "{}"),
+                "POST", "/api/v1/posts", 400, 40000);
+        // PATCH：缺 version
+        verifiedError(authed(patch("/api/v1/posts/{postId}", postId), user)
+                        .content("{\"content\":\"缺版本\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 400, 40000);
+
+        verifiedError(get("/api/v1/me/posts").param("limit", "0")
+                        .header("Authorization", "Bearer " + token(user)),
+                "GET", "/api/v1/me/posts", 400, 40000);
+        verifiedError(get("/api/v1/feed").param("cursor", "not-a-cursor")
+                        .header("Authorization", "Bearer " + token(user)),
+                "GET", "/api/v1/feed", 400, 40000);
+        verifiedError(get("/api/v1/posts/{postId}/comments", postId).param("limit", "101")
+                        .header("Authorization", "Bearer " + token(user)),
+                "GET", "/api/v1/posts/{postId}/comments", 400, 40000);
+        verifiedError(authed(post("/api/v1/posts/{postId}/comments", postId), user)
+                        .header(IDEMPOTENCY_KEY, UUID.randomUUID().toString())
+                        .content("{}"),
+                "POST", "/api/v1/posts/{postId}/comments", 400, 40000);
+        verifiedError(get("/api/v1/me/bookmarks").param("cursor", "broken")
+                        .header("Authorization", "Bearer " + token(user)),
+                "GET", "/api/v1/me/bookmarks", 400, 40000);
+    }
+
+    @Test
+    @Order(8)
+    void antiEnumerationAndPermissionErrorsMatchContract() throws Exception {
+        UUID author = newUser();
+        UUID other = newUser();
+        String ghost = UUID.randomUUID().toString();
+
+        // -- 40403：帖子防枚举（不存在 / 他人 draft 同响应）--
+        verifiedError(get("/api/v1/posts/{postId}", ghost)
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/posts/{postId}", 404, 40403);
+        String draftId = newPost(author, "{\"content\":\"他人不可见草稿\"}");
+        verifiedError(authed(patch("/api/v1/posts/{postId}", draftId), other)
+                        .content("{\"version\":0,\"content\":\"越权\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 404, 40403);
+        verifiedError(authed(delete("/api/v1/posts/{postId}", ghost), author),
+                "DELETE", "/api/v1/posts/{postId}", 404, 40403);
+        verifiedError(get("/api/v1/posts/{postId}/comments", draftId)
+                        .header("Authorization", "Bearer " + token(other)),
+                "GET", "/api/v1/posts/{postId}/comments", 404, 40403);
+        // 互动面 = 帖子公开面：作者本人草稿同样 40403
+        verifiedError(authed(put("/api/v1/posts/{postId}/like", draftId), author),
+                "PUT", "/api/v1/posts/{postId}/like", 404, 40403);
+        verifiedError(authed(delete("/api/v1/posts/{postId}/like", draftId), author),
+                "DELETE", "/api/v1/posts/{postId}/like", 404, 40403);
+        verifiedError(authed(put("/api/v1/posts/{postId}/bookmark", ghost), author),
+                "PUT", "/api/v1/posts/{postId}/bookmark", 404, 40403);
+        verifiedError(authed(delete("/api/v1/posts/{postId}/bookmark", ghost), author),
+                "DELETE", "/api/v1/posts/{postId}/bookmark", 404, 40403);
+
+        // -- 创建帖子的 404 双业务码：40401 幽灵宠物 / 40405 幽灵 asset --
+        verifiedError(createPostRequest(author, UUID.randomUUID().toString(), """
+                        {"content":"幽灵宠物","petId":"%s"}
+                        """.formatted(ghost)),
+                "POST", "/api/v1/posts", 404, 40401);
+        verifiedError(createPostRequest(author, UUID.randomUUID().toString(), """
+                        {"content":"幽灵媒体","media":[{"assetId":"%s"}]}
+                        """.formatted(ghost)),
+                "POST", "/api/v1/posts", 404, 40405);
+
+        // -- 评论的 404 双业务码：40403 帖子不可见 / 40406 幽灵 @ 目标 --
+        String postId = newPublishedPost(author, "契约错误评论帖");
+        verifiedError(authed(post("/api/v1/posts/{postId}/comments", draftId), other)
+                        .header(IDEMPOTENCY_KEY, UUID.randomUUID().toString())
+                        .content("{\"content\":\"评论他人草稿\"}"),
+                "POST", "/api/v1/posts/{postId}/comments", 404, 40403);
+        verifiedError(authed(post("/api/v1/posts/{postId}/comments", postId), other)
+                        .header(IDEMPOTENCY_KEY, UUID.randomUUID().toString())
+                        .content("""
+                                {"content":"@ 幽灵","replyToUserId":"%s"}
+                                """.formatted(ghost)),
+                "POST", "/api/v1/posts/{postId}/comments", 404, 40406);
+        verifiedError(authed(delete("/api/v1/comments/{commentId}", ghost), author),
+                "DELETE", "/api/v1/comments/{commentId}", 404, 40404);
+
+        // -- 40406：关注三端点的幽灵目标 --
+        verifiedError(authed(put("/api/v1/users/{userId}/follow", ghost), author),
+                "PUT", "/api/v1/users/{userId}/follow", 404, 40406);
+        verifiedError(authed(delete("/api/v1/users/{userId}/follow", ghost), author),
+                "DELETE", "/api/v1/users/{userId}/follow", 404, 40406);
+        verifiedError(get("/api/v1/users/{userId}/follow-stats", ghost)
+                        .header("Authorization", "Bearer " + token(author)),
+                "GET", "/api/v1/users/{userId}/follow-stats", 404, 40406);
+
+        // -- 40301：可见但无权限（他人已发布帖改/删、他人可见评论删——含帖主）--
+        verifiedError(authed(patch("/api/v1/posts/{postId}", postId), other)
+                        .content("{\"version\":0,\"content\":\"越权改\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 403, 40301);
+        verifiedError(authed(delete("/api/v1/posts/{postId}", postId), other),
+                "DELETE", "/api/v1/posts/{postId}", 403, 40301);
+        String commentId = newComment(other, postId, "帖主也删不得");
+        verifiedError(authed(delete("/api/v1/comments/{commentId}", commentId), author),
+                "DELETE", "/api/v1/comments/{commentId}", 403, 40301);
+    }
+
+    @Test
+    @Order(9)
+    void conflictAndRuleErrorsMatchContract() throws Exception {
+        UUID author = newUser();
+        UUID self = author;
+
+        // -- 409/40905：同幂等键不同 payload（帖子与评论）--
+        String key = UUID.randomUUID().toString();
+        verified(createPostRequest(author, key, "{\"content\":\"首次提交\"}"),
+                "POST", "/api/v1/posts", 201);
+        verifiedError(createPostRequest(author, key, "{\"content\":\"同键不同内容\"}"),
+                "POST", "/api/v1/posts", 409, 40905);
+
+        String postId = newPublishedPost(author, "契约冲突帖");
+        String commentKey = UUID.randomUUID().toString();
+        verified(authed(post("/api/v1/posts/{postId}/comments", postId), author)
+                        .header(IDEMPOTENCY_KEY, commentKey)
+                        .content("{\"content\":\"首次评论\"}"),
+                "POST", "/api/v1/posts/{postId}/comments", 201);
+        verifiedError(authed(post("/api/v1/posts/{postId}/comments", postId), author)
+                        .header(IDEMPOTENCY_KEY, commentKey)
+                        .content("{\"content\":\"同键不同评论\"}"),
+                "POST", "/api/v1/posts/{postId}/comments", 409, 40905);
+
+        // -- 409/40902：乐观锁过期（先成功一次把 version 顶到 1）--
+        verified(authed(patch("/api/v1/posts/{postId}", postId), author)
+                        .content("{\"version\":0,\"content\":\"第一次改\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 200);
+        verifiedError(authed(patch("/api/v1/posts/{postId}", postId), author)
+                        .content("{\"version\":0,\"content\":\"过期版本\"}"),
+                "PATCH", "/api/v1/posts/{postId}", 409, 40902);
+
+        // -- 422/42203：引用本人 uploading asset（创建与编辑）--
+        UUID uploading = CommunityTestData.insertAsset(jdbcClient, author, "uploading");
+        verifiedError(createPostRequest(author, UUID.randomUUID().toString(), """
+                        {"content":"未就绪媒体","media":[{"assetId":"%s"}]}
+                        """.formatted(uploading)),
+                "POST", "/api/v1/posts", 422, 42203);
+        verifiedError(authed(patch("/api/v1/posts/{postId}", postId), author)
+                        .content("""
+                                {"version":1,"media":[{"assetId":"%s"}]}
+                                """.formatted(uploading)),
+                "PATCH", "/api/v1/posts/{postId}", 422, 42203);
+
+        // -- 422/42204：自关注（仅 PUT；自取关 200 已在 Order(5) 语义内）--
+        verifiedError(authed(put("/api/v1/users/{userId}/follow", self), self),
+                "PUT", "/api/v1/users/{userId}/follow", 422, 42204);
+    }
+
+    // ---- 快照与覆盖门禁 -------------------------------------------------
+
+    /**
+     * 冻结快照守卫：与 pet/auth 侧同一纪律——正典契约升版时必须同步复制新快照
+     * 并更新期望值，忘记同步在 CI 立即变红。
+     */
+    @Test
+    @Order(98)
+    void frozenSnapshotIsTheExpectedContractVersion() {
+        assertThat(CONTRACT.version()).isEqualTo("1.3.0");
+        assertThat(CONTRACT.paths()).hasSize(31);
+        assertThat(CONTRACT.operations()).hasSize(43);
+        assertThat(CONTRACT.schemas()).hasSize(72);
+        assertThat(CONTRACT.operationsTagged(
+                Set.of("posts", "feed", "comments", "interactions", "follows")))
+                .containsExactlyInAnyOrderElementsOf(COMMUNITY_OPERATIONS);
+    }
+
+    /**
+     * 全矩阵覆盖门禁：community 域 17 个操作声明的每个 (操作, 状态码) 都必须被
+     * 前面的测试真实触发并通过契约校验（64 个单元格，无豁免）。
+     */
+    @Test
+    @Order(99)
+    void everyDeclaredResponseCellIsExercised() {
+        List<String> missing = new ArrayList<>();
+        for (String op : COMMUNITY_OPERATIONS) {
+            for (int status : CONTRACT.responseStatuses(op)) {
+                String cell = op + " " + status;
+                if (!COVERED.contains(cell)) {
+                    missing.add(cell);
+                }
+            }
+        }
+        assertThat(missing).as("契约声明但未被契约测试触发的响应单元格").isEmpty();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/contract/ContractValidator.java

@@ -0,0 +1,256 @@
+package com.patbond.patbond.community.contract;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeParseException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import static com.patbond.patbond.community.contract.OpenApiContract.cast;
+import static com.patbond.patbond.community.contract.OpenApiContract.list;
+import static com.patbond.patbond.community.contract.OpenApiContract.map;
+
+/**
+ * Validates an actual HTTP response against the frozen contract, strictly:
+ *
+ * <ul>
+ *   <li>the operation and the status must be declared;</li>
+ *   <li>required fields must be present; a null value needs {@code nullable};</li>
+ *   <li>fields the schema does not declare are rejected (this is what catches
+ *       a renamed or newly leaked field — plain OpenAPI semantics would allow
+ *       extra properties, but the frozen contract is "exactly these fields");</li>
+ *   <li>types, enum membership, uuid / date-time / date formats and
+ *       min/max(Length) bounds are checked.</li>
+ * </ul>
+ *
+ * Behavioural semantics (state machines, anti-enumeration, permission logic)
+ * stay with the existing integration tests — this class only pins structure.
+ */
+final class ContractValidator {
+
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    private final OpenApiContract contract;
+
+    ContractValidator(OpenApiContract contract) {
+        this.contract = contract;
+    }
+
+    /**
+     * @return drift findings, empty when the response conforms; each entry is
+     *         a human-readable "where: what" line
+     */
+    List<String> validateResponse(String method, String pathTemplate, int status, String body) {
+        List<String> errors = new ArrayList<>();
+        String opKey = method + " " + pathTemplate;
+        Map<String, Object> op = contract.operation(opKey);
+        if (op == null) {
+            errors.add("契约未声明该操作: " + opKey);
+            return errors;
+        }
+        Object respNode = map(op, "responses").get(String.valueOf(status));
+        if (respNode == null) {
+            errors.add("契约未为 " + opKey + " 声明状态码 " + status);
+            return errors;
+        }
+        Map<String, Object> content = map(contract.resolve(cast(respNode)), "content");
+        if (content == null) {
+            return errors; // response declared without a body
+        }
+        Map<String, Object> schema = map(map(content, "application/json"), "schema");
+        if (schema == null) {
+            errors.add(opKey + " " + status + ": 契约声明了 content 但无 application/json schema");
+            return errors;
+        }
+        JsonNode node;
+        try {
+            node = MAPPER.readTree(body);
+        } catch (JsonProcessingException e) {
+            errors.add(opKey + " " + status + ": 响应体不是合法 JSON: " + e.getOriginalMessage());
+            return errors;
+        }
+        validate(schema, node, "$", errors);
+        return errors;
+    }
+
+    private void validate(Map<String, Object> rawSchema, JsonNode node, String loc, List<String> errors) {
+        Map<String, Object> schema = effectiveSchema(rawSchema);
+        if (node == null || node.isMissingNode()) {
+            errors.add(loc + ": 字段缺失");
+            return;
+        }
+        if (node.isNull()) {
+            if (!Boolean.TRUE.equals(schema.get("nullable"))) {
+                errors.add(loc + ": 为 null，但契约未声明 nullable");
+            }
+            return;
+        }
+        List<Object> allowed = list(schema, "enum");
+        if (allowed != null && !enumMatches(allowed, node)) {
+            errors.add(loc + ": 值 " + node + " 不在契约枚举 " + allowed + " 内");
+        }
+        String type = (String) schema.get("type");
+        if (type == null) {
+            type = schema.containsKey("properties") ? "object" : null;
+        }
+        if (type == null) {
+            return;
+        }
+        switch (type) {
+            case "object" -> validateObject(schema, node, loc, errors);
+            case "array" -> validateArray(schema, node, loc, errors);
+            case "string" -> validateString(schema, node, loc, errors);
+            case "integer" -> {
+                if (!node.isIntegralNumber()) {
+                    errors.add(loc + ": 应为 integer，实际 " + node.getNodeType() + " " + node);
+                } else {
+                    checkRange(schema, node.decimalValue(), loc, errors);
+                }
+            }
+            case "number" -> {
+                if (!node.isNumber()) {
+                    errors.add(loc + ": 应为 number，实际 " + node.getNodeType() + " " + node);
+                } else {
+                    checkRange(schema, node.decimalValue(), loc, errors);
+                }
+            }
+            case "boolean" -> {
+                if (!node.isBoolean()) {
+                    errors.add(loc + ": 应为 boolean，实际 " + node.getNodeType() + " " + node);
+                }
+            }
+            default -> errors.add(loc + ": 契约测试不支持的 type " + type);
+        }
+    }
+
+    /**
+     * Resolves $refs and flattens the v1.3.0 {@code nullable + allOf: [$ref]}
+     * pattern into one plain schema (branch keys first, sibling keys — e.g.
+     * the outer {@code nullable} — win). The frozen contract only ever uses
+     * single-branch allOf, so a shallow merge is exact; overlapping
+     * {@code properties} across branches would need a deep merge and are not
+     * supported.
+     */
+    private Map<String, Object> effectiveSchema(Map<String, Object> rawSchema) {
+        Map<String, Object> schema = contract.resolve(rawSchema);
+        List<Object> allOf = list(schema, "allOf");
+        if (allOf == null) {
+            return schema;
+        }
+        Map<String, Object> merged = new LinkedHashMap<>();
+        for (Object branch : allOf) {
+            merged.putAll(effectiveSchema(cast(branch)));
+        }
+        schema.forEach((key, value) -> {
+            if (!"allOf".equals(key)) {
+                merged.put(key, value);
+            }
+        });
+        return merged;
+    }
+
+    private void validateObject(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isObject()) {
+            errors.add(loc + ": 应为 object，实际 " + node.getNodeType());
+            return;
+        }
+        Map<String, Object> props = map(schema, "properties");
+        List<Object> required = list(schema, "required");
+        if (required != null) {
+            for (Object r : required) {
+                if (!node.has((String) r)) {
+                    errors.add(loc + "." + r + ": 契约必填字段缺失");
+                }
+            }
+        }
+        Object additional = schema.get("additionalProperties");
+        boolean open = Boolean.TRUE.equals(additional) || additional instanceof Map;
+        Iterator<Map.Entry<String, JsonNode>> fields = node.fields();
+        while (fields.hasNext()) {
+            Map.Entry<String, JsonNode> field = fields.next();
+            Map<String, Object> propSchema = props == null ? null : cast(props.get(field.getKey()));
+            if (propSchema != null) {
+                validate(propSchema, field.getValue(), loc + "." + field.getKey(), errors);
+            } else if (!open) {
+                errors.add(loc + "." + field.getKey() + ": 契约未声明的字段（结构漂移）");
+            }
+        }
+    }
+
+    private void validateArray(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isArray()) {
+            errors.add(loc + ": 应为 array，实际 " + node.getNodeType());
+            return;
+        }
+        Map<String, Object> items = map(schema, "items");
+        if (items == null) {
+            return;
+        }
+        int i = 0;
+        for (JsonNode element : node) {
+            validate(items, element, loc + "[" + i++ + "]", errors);
+        }
+    }
+
+    private void validateString(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isTextual()) {
+            errors.add(loc + ": 应为 string，实际 " + node.getNodeType() + " " + node);
+            return;
+        }
+        String value = node.asText();
+        String format = (String) schema.get("format");
+        if (format != null) {
+            try {
+                switch (format) {
+                    case "uuid" -> {
+                        if (value.length() != 36) {
+                            throw new IllegalArgumentException("非规范 UUID 长度");
+                        }
+                        java.util.UUID.fromString(value);
+                    }
+                    case "date-time" -> OffsetDateTime.parse(value);
+                    case "date" -> LocalDate.parse(value);
+                    default -> { /* password 等纯标注格式不校验 */ }
+                }
+            } catch (IllegalArgumentException | DateTimeParseException e) {
+                errors.add(loc + ": \"" + value + "\" 不符合 format=" + format);
+            }
+        }
+        if (schema.get("minLength") instanceof Number min && value.length() < min.intValue()) {
+            errors.add(loc + ": 长度 " + value.length() + " 小于契约 minLength " + min);
+        }
+        if (schema.get("maxLength") instanceof Number max && value.length() > max.intValue()) {
+            errors.add(loc + ": 长度 " + value.length() + " 大于契约 maxLength " + max);
+        }
+    }
+
+    private static void checkRange(Map<String, Object> schema, BigDecimal value, String loc, List<String> errors) {
+        if (schema.get("minimum") instanceof Number min
+                && value.compareTo(new BigDecimal(min.toString())) < 0) {
+            errors.add(loc + ": 值 " + value + " 小于契约 minimum " + min);
+        }
+        if (schema.get("maximum") instanceof Number max
+                && value.compareTo(new BigDecimal(max.toString())) > 0) {
+            errors.add(loc + ": 值 " + value + " 大于契约 maximum " + max);
+        }
+    }
+
+    private static boolean enumMatches(List<Object> allowed, JsonNode node) {
+        if (node.isTextual()) {
+            return allowed.contains(node.asText());
+        }
+        if (node.isIntegralNumber()) {
+            long v = node.longValue();
+            return allowed.stream().anyMatch(a -> a instanceof Number n && n.longValue() == v);
+        }
+        return false;
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/contract/OpenApiContract.java

@@ -0,0 +1,151 @@
+package com.patbond.patbond.community.contract;
+
+import org.yaml.snakeyaml.Yaml;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * The frozen v1.3.0 OpenAPI contract, loaded from the test-resource snapshot
+ * {@code /contract/openapi-v1.3.0.yaml}.
+ *
+ * <p><b>Sync discipline (T2-09, extended by T3-19)</b>: the canonical
+ * contract lives in the doc repo at {@code docs/api/openapi.yaml}; this
+ * snapshot is a byte-identical copy taken at freeze time, and this class is
+ * the module-local copy of the pet module's contract framework (same
+ * per-module duplication discipline as BearerAuthFilter). Whenever the
+ * canonical contract changes, copy it into every framework-carrying module
+ * (patbond-pet / patbond-auth / patbond-community / patbond-user) under the
+ * new version's file name and update each conformance test (expected version
+ * + snapshot counts). The guard test on {@code info.version} makes a forgotten
+ * sync fail loudly in CI instead of silently testing against a stale
+ * contract.
+ *
+ * <p>Only the subset of OpenAPI 3.0 this contract actually uses is supported:
+ * local {@code #/} refs, plain types, {@code nullable}, {@code enum},
+ * {@code required}, {@code properties}, {@code items}, and the v1.3.0
+ * single-branch {@code nullable + allOf: [$ref]} pattern (merged in
+ * {@link ContractValidator}) — no oneOf/anyOf.
+ */
+final class OpenApiContract {
+
+    static final String RESOURCE = "/contract/openapi-v1.3.0.yaml";
+
+    private static final Set<String> HTTP_METHODS =
+            Set.of("get", "put", "post", "delete", "options", "head", "patch", "trace");
+
+    private final Map<String, Object> root;
+
+    private OpenApiContract(Map<String, Object> root) {
+        this.root = root;
+    }
+
+    static OpenApiContract load() {
+        try (InputStream in = Objects.requireNonNull(
+                OpenApiContract.class.getResourceAsStream(RESOURCE),
+                "契约快照缺失: " + RESOURCE)) {
+            return new OpenApiContract(new Yaml().load(in));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    String version() {
+        return (String) map(root, "info").get("version");
+    }
+
+    Map<String, Object> paths() {
+        return map(root, "paths");
+    }
+
+    Map<String, Object> schemas() {
+        return map(map(root, "components"), "schemas");
+    }
+
+    /** All declared operations as "METHOD pathTemplate" (insertion order). */
+    Set<String> operations() {
+        Set<String> ops = new LinkedHashSet<>();
+        paths().forEach((path, item) -> cast(item).forEach((method, op) -> {
+            if (HTTP_METHODS.contains(method)) {
+                ops.add(method.toUpperCase(Locale.ROOT) + " " + path);
+            }
+        }));
+        return ops;
+    }
+
+    /** Operations whose first tag is in {@code tags}, as "METHOD pathTemplate". */
+    Set<String> operationsTagged(Set<String> tags) {
+        Set<String> ops = new LinkedHashSet<>();
+        for (String key : operations()) {
+            List<Object> opTags = list(operation(key), "tags");
+            if (opTags != null && opTags.stream().anyMatch(tags::contains)) {
+                ops.add(key);
+            }
+        }
+        return ops;
+    }
+
+    /** Declared response statuses of an operation, as ints. */
+    Set<Integer> responseStatuses(String operationKey) {
+        Set<Integer> statuses = new LinkedHashSet<>();
+        map(operation(operationKey), "responses")
+                .keySet().forEach(s -> statuses.add(Integer.parseInt(s)));
+        return statuses;
+    }
+
+    /** The single 2xx status the operation declares. */
+    int successStatus(String operationKey) {
+        return responseStatuses(operationKey).stream()
+                .filter(s -> s >= 200 && s < 300)
+                .reduce((a, b) -> {
+                    throw new IllegalStateException("多个 2xx 响应: " + operationKey);
+                })
+                .orElseThrow(() -> new IllegalStateException("无 2xx 响应: " + operationKey));
+    }
+
+    /** Operation object for "METHOD pathTemplate", or null when undeclared. */
+    Map<String, Object> operation(String operationKey) {
+        String[] parts = operationKey.split(" ", 2);
+        Map<String, Object> pathItem = map(paths(), parts[1]);
+        return pathItem == null ? null : map(pathItem, parts[0].toLowerCase(Locale.ROOT));
+    }
+
+    /** Follows local $ref chains; non-ref maps come back unchanged. */
+    Map<String, Object> resolve(Map<String, Object> node) {
+        while (node != null && node.get("$ref") instanceof String ref) {
+            if (!ref.startsWith("#/")) {
+                throw new IllegalStateException("仅支持本地 $ref: " + ref);
+            }
+            Map<String, Object> cur = root;
+            for (String seg : ref.substring(2).split("/")) {
+                cur = map(cur, seg);
+                if (cur == null) {
+                    throw new IllegalStateException("$ref 指向不存在的节点: " + ref);
+                }
+            }
+            node = cur;
+        }
+        return node;
+    }
+
+    @SuppressWarnings("unchecked")
+    static Map<String, Object> cast(Object o) {
+        return (Map<String, Object>) o;
+    }
+
+    static Map<String, Object> map(Map<String, Object> m, String key) {
+        return m == null ? null : cast(m.get(key));
+    }
+
+    @SuppressWarnings("unchecked")
+    static List<Object> list(Map<String, Object> m, String key) {
+        return m == null ? null : (List<Object>) m.get(key);
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/interaction/CommentIntegrationTest.java

@@ -0,0 +1,363 @@
+package com.patbond.patbond.community.interaction;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.patbond.patbond.community.post.PostApiTestBase;
+import com.patbond.patbond.community.support.CommunityTestData;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * T3-07 flat comments on the real database: the six canonical paths, the
+ * ADR-019 keyed-idempotency matrix, the interaction-surface 40403 merge,
+ * DESC keyset pagination and the same-transaction comment_count invariant.
+ * These assertions are T3-10 freeze input for the comment domain.
+ */
+class CommentIntegrationTest extends PostApiTestBase {
+
+    @Test
+    void createCommentReturnsFullShapeAndBumpsCount() throws Exception {
+        UUID author = newUser();
+        UUID commenter = newUser();
+        CommunityTestData.setNickname(jdbcClient, commenter, "毛豆妈");
+        String postId = publishPost(author);
+
+        mockMvc.perform(commentRequest(commenter, postId, UUID.randomUUID().toString(),
+                        "{\"content\": \"  说得好！  \"}"))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.code").value(0))
+                .andExpect(jsonPath("$.data.id").isNotEmpty())
+                .andExpect(jsonPath("$.data.postId").value(postId))
+                .andExpect(jsonPath("$.data.author.userId").value(commenter.toString()))
+                .andExpect(jsonPath("$.data.author.nickname").value("毛豆妈"))
+                .andExpect(jsonPath("$.data.replyToUser").isEmpty())
+                .andExpect(jsonPath("$.data.content").value("说得好！"))
+                .andExpect(jsonPath("$.data.createdAt").isNotEmpty());
+
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId), author))
+                .andExpect(jsonPath("$.data.commentCount").value(1));
+    }
+
+    @Test
+    void createWithReplyToUserCarriesReplySummary() throws Exception {
+        UUID author = newUser();
+        UUID replyTarget = newUser();
+        CommunityTestData.setNickname(jdbcClient, replyTarget, "被@的人");
+        String postId = publishPost(author);
+
+        mockMvc.perform(commentRequest(author, postId, UUID.randomUUID().toString(),
+                        "{\"content\": \"回复你\", \"replyToUserId\": \"" + replyTarget + "\"}"))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.data.replyToUser.userId").value(replyTarget.toString()))
+                .andExpect(jsonPath("$.data.replyToUser.nickname").value("被@的人"));
+    }
+
+    @Test
+    void contentAndKeyValidationAnswer40000() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+
+        mockMvc.perform(commentRequest(user, postId, UUID.randomUUID().toString(),
+                        "{\"content\": \"   \"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(commentRequest(user, postId, UUID.randomUUID().toString(),
+                        "{\"content\": \"" + "长".repeat(2001) + "\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        // Idempotency-Key: missing header, blank, oversized
+        mockMvc.perform(authed(post("/api/v1/posts/" + postId + "/comments"), user)
+                        .content("{\"content\": \"没带键\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(commentRequest(user, postId, "   ", "{\"content\": \"空白键\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(commentRequest(user, postId, "k".repeat(129), "{\"content\": \"超长键\"}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void replyToAbsentOrDeletedUserAnswers40406() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        UUID ghost = UUID.randomUUID();
+        UUID cancelled = newUser();
+        jdbcClient.sql("UPDATE identity.users SET status = 'deleted', deleted_at = now()"
+                        + " WHERE id = :id")
+                .param("id", cancelled)
+                .update();
+
+        for (UUID target : List.of(ghost, cancelled)) {
+            mockMvc.perform(commentRequest(user, postId, UUID.randomUUID().toString(),
+                            "{\"content\": \"@不存在\", \"replyToUserId\": \"" + target + "\"}"))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40406))
+                    .andExpect(jsonPath("$.message").value("用户不存在"));
+        }
+    }
+
+    @Test
+    void commentPathsOnInvisiblePostsAnswerIdentical40403() throws Exception {
+        UUID author = newUser();
+        UUID stranger = newUser();
+        String ownDraft = createPost(author, "{\"content\": \"草稿\"}").get("id").asText();
+        String hidden = publishPost(author);
+        jdbcClient.sql("UPDATE community.posts SET status = 'hidden' WHERE id = :id")
+                .param("id", UUID.fromString(hidden))
+                .update();
+        String deleted = publishPost(author);
+        mockMvc.perform(authed(delete("/api/v1/posts/" + deleted), author))
+                .andExpect(status().isOk());
+
+        Set<String> bodies = new LinkedHashSet<>();
+        // own draft (the interaction surface is the PUBLIC face — the
+        // author's own draft is not commentable), hidden, deleted, absent
+        for (String target : List.of(ownDraft, hidden, deleted, UUID.randomUUID().toString())) {
+            MvcResult postResult = mockMvc.perform(
+                            commentRequest(author, target, UUID.randomUUID().toString(),
+                                    "{\"content\": \"评一下\"}"))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40403))
+                    .andReturn();
+            bodies.add(postResult.getResponse().getContentAsString());
+            MvcResult listResult = mockMvc.perform(
+                            authed(get("/api/v1/posts/" + target + "/comments"), stranger))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40403))
+                    .andReturn();
+            bodies.add(listResult.getResponse().getContentAsString());
+        }
+        // anti-enumeration: every invisible case is byte-identical
+        assertThat(bodies).hasSize(1);
+    }
+
+    @Test
+    void keyedReplayReturnsFirstCommentWithoutDoubleCounting() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        String key = UUID.randomUUID().toString();
+
+        String first = data(mockMvc.perform(commentRequest(user, postId, key,
+                        "{\"content\": \"就一条\"}"))
+                .andExpect(status().isCreated())
+                .andReturn()).get("id").asText();
+        String replay = data(mockMvc.perform(commentRequest(user, postId, key,
+                        "{\"content\": \"就一条\"}"))
+                .andExpect(status().isCreated())
+                .andReturn()).get("id").asText();
+
+        assertThat(replay).isEqualTo(first);
+        assertThat(countRows("community.comments", "post_id", postId)).isEqualTo(1);
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId), user))
+                .andExpect(jsonPath("$.data.commentCount").value(1));
+    }
+
+    @Test
+    void sameKeyDifferentPayloadAnswers40905() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        String key = UUID.randomUUID().toString();
+        mockMvc.perform(commentRequest(user, postId, key, "{\"content\": \"甲\"}"))
+                .andExpect(status().isCreated());
+        mockMvc.perform(commentRequest(user, postId, key, "{\"content\": \"乙\"}"))
+                .andExpect(status().isConflict())
+                .andExpect(jsonPath("$.code").value(40905));
+    }
+
+    @Test
+    void idempotencyKeysAreScopedPerAuthor() throws Exception {
+        UUID one = newUser();
+        UUID two = newUser();
+        String postId = publishPost(one);
+        String shared = UUID.randomUUID().toString();
+        mockMvc.perform(commentRequest(one, postId, shared, "{\"content\": \"同键\"}"))
+                .andExpect(status().isCreated());
+        mockMvc.perform(commentRequest(two, postId, shared, "{\"content\": \"同键\"}"))
+                .andExpect(status().isCreated());
+        assertThat(countRows("community.comments", "post_id", postId)).isEqualTo(2);
+    }
+
+    @Test
+    void replayAfterFirstCommentDeletedAnswers40404() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        String key = UUID.randomUUID().toString();
+        String commentId = data(mockMvc.perform(commentRequest(user, postId, key,
+                        "{\"content\": \"将被删\"}"))
+                .andReturn()).get("id").asText();
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), user))
+                .andExpect(status().isOk());
+
+        mockMvc.perform(commentRequest(user, postId, key, "{\"content\": \"将被删\"}"))
+                .andExpect(status().isNotFound())
+                .andExpect(jsonPath("$.code").value(40404));
+    }
+
+    @Test
+    void listPagesNewestFirstWithoutLossOrOverlap() throws Exception {
+        UUID author = newUser();
+        UUID reader = newUser();
+        String postId = publishPost(author);
+        List<String> created = new ArrayList<>();
+        for (int i = 0; i < 7; i++) {
+            created.add(data(mockMvc.perform(commentRequest(author, postId,
+                            UUID.randomUUID().toString(), "{\"content\": \"评论" + i + "\"}"))
+                    .andReturn()).get("id").asText());
+        }
+        String deletedId = created.get(3);
+        mockMvc.perform(authed(delete("/api/v1/comments/" + deletedId), author))
+                .andExpect(status().isOk());
+
+        List<String> seen = new ArrayList<>();
+        String cursor = null;
+        for (int page = 0; page < 3; page++) {
+            String url = "/api/v1/posts/" + postId + "/comments?limit=3"
+                    + (cursor == null ? "" : "&cursor=" + cursor);
+            JsonNode body = data(mockMvc.perform(authed(get(url), reader))
+                    .andExpect(status().isOk())
+                    .andReturn());
+            body.get("items").forEach(item -> seen.add(item.get("id").asText()));
+            if (!body.get("hasMore").asBoolean()) {
+                assertThat(body.get("nextCursor").isNull()).isTrue();
+                break;
+            }
+            cursor = body.get("nextCursor").asText();
+        }
+        List<String> expected = new ArrayList<>(created);
+        java.util.Collections.reverse(expected);
+        expected.remove(deletedId);
+        assertThat(seen).containsExactlyElementsOf(expected);
+    }
+
+    @Test
+    void listRejectsBadPagingInput() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId + "/comments?limit=0"), user))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId + "/comments?cursor=不是游标"), user))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(authed(get("/api/v1/posts/不是UUID/comments"), user))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void deleteWalksThePermissionBoundary() throws Exception {
+        UUID author = newUser();
+        UUID commenter = newUser();
+        UUID stranger = newUser();
+        String postId = publishPost(author);
+        String commentId = data(mockMvc.perform(commentRequest(commenter, postId,
+                        UUID.randomUUID().toString(), "{\"content\": \"别人的评论\"}"))
+                .andReturn()).get("id").asText();
+
+        // a visible comment deleted by a non-author (the post's owner
+        // included — D3-7: 帖主删他人评论首版不做) is 403/40301
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), stranger))
+                .andExpect(status().isForbidden())
+                .andExpect(jsonPath("$.code").value(40301));
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), author))
+                .andExpect(status().isForbidden())
+                .andExpect(jsonPath("$.code").value(40301));
+
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), commenter))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.code").value(0));
+        String state = jdbcClient.sql(
+                        "SELECT status || ':' || (deleted_at IS NOT NULL) FROM community.comments"
+                                + " WHERE id = :id")
+                .param("id", UUID.fromString(commentId))
+                .query(String.class)
+                .single();
+        assertThat(state).isEqualTo("deleted:true");
+
+        // repeat delete and absent id merge into 404/40404
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), commenter))
+                .andExpect(status().isNotFound())
+                .andExpect(jsonPath("$.code").value(40404));
+        mockMvc.perform(authed(delete("/api/v1/comments/" + UUID.randomUUID()), commenter))
+                .andExpect(status().isNotFound())
+                .andExpect(jsonPath("$.code").value(40404));
+    }
+
+    @Test
+    void deleteOnCommentOfDeletedPostAnswers40404() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        String commentId = data(mockMvc.perform(commentRequest(user, postId,
+                        UUID.randomUUID().toString(), "{\"content\": \"帖没了\"}"))
+                .andReturn()).get("id").asText();
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId), user))
+                .andExpect(status().isOk());
+
+        mockMvc.perform(authed(delete("/api/v1/comments/" + commentId), user))
+                .andExpect(status().isNotFound())
+                .andExpect(jsonPath("$.code").value(40404));
+    }
+
+    @Test
+    void commentCountReconcilesWithVisibleRows() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        List<String> ids = new ArrayList<>();
+        for (int i = 0; i < 3; i++) {
+            ids.add(data(mockMvc.perform(commentRequest(user, postId,
+                            UUID.randomUUID().toString(), "{\"content\": \"第" + i + "条\"}"))
+                    .andReturn()).get("id").asText());
+        }
+        mockMvc.perform(authed(delete("/api/v1/comments/" + ids.get(0)), user))
+                .andExpect(status().isOk());
+
+        long column = jdbcClient.sql("SELECT comment_count FROM community.posts WHERE id = :id")
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+        long visible = jdbcClient.sql("""
+                        SELECT count(*) FROM community.comments
+                        WHERE post_id = :id AND status = 'visible'
+                        """)
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+        assertThat(column).isEqualTo(2).isEqualTo(visible);
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId + "/comments"), user))
+                .andExpect(jsonPath("$.data.items.length()").value(2));
+    }
+
+    private String publishPost(UUID author) throws Exception {
+        return createPost(author, "{\"content\": \"被评论的帖子\", \"status\": \"published\"}")
+                .get("id").asText();
+    }
+
+    private MockHttpServletRequestBuilder commentRequest(UUID userId, String postId, String key,
+                                                         String body) {
+        return authed(post("/api/v1/posts/" + postId + "/comments"), userId)
+                .header("Idempotency-Key", key)
+                .content(body);
+    }
+
+    private long countRows(String table, String column, String value) {
+        return jdbcClient.sql("SELECT count(*) FROM " + table + " WHERE " + column + " = :value")
+                .param("value", UUID.fromString(value))
+                .query(Long.class)
+                .single();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/interaction/FollowIntegrationTest.java

@@ -0,0 +1,156 @@
+package com.patbond.patbond.community.interaction;
+
+import com.patbond.patbond.community.post.PostApiTestBase;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * T3-07 minimal follow surface on the real database: idempotent
+ * follow/unfollow with authoritative state, the 42204 self-follow gate,
+ * the 40406 target gate (absent and 注销 merged), the numbers endpoint
+ * and true concurrent convergence on the composite primary key.
+ */
+class FollowIntegrationTest extends PostApiTestBase {
+
+    @Test
+    void followLifecycleIsIdempotentWithAuthoritativeState() throws Exception {
+        UUID follower = newUser();
+        UUID target = newUser();
+
+        mockMvc.perform(authed(put("/api/v1/users/" + target + "/follow"), follower))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.following").value(true))
+                .andExpect(jsonPath("$.data.followerCount").value(1));
+        mockMvc.perform(authed(put("/api/v1/users/" + target + "/follow"), follower))
+                .andExpect(jsonPath("$.data.following").value(true))
+                .andExpect(jsonPath("$.data.followerCount").value(1));
+
+        mockMvc.perform(authed(delete("/api/v1/users/" + target + "/follow"), follower))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.following").value(false))
+                .andExpect(jsonPath("$.data.followerCount").value(0));
+        mockMvc.perform(authed(delete("/api/v1/users/" + target + "/follow"), follower))
+                .andExpect(jsonPath("$.data.following").value(false))
+                .andExpect(jsonPath("$.data.followerCount").value(0));
+        assertThat(followRows(target)).isEqualTo(0);
+    }
+
+    @Test
+    void selfFollowIsRejectedWith42204() throws Exception {
+        UUID user = newUser();
+        mockMvc.perform(authed(put("/api/v1/users/" + user + "/follow"), user))
+                .andExpect(status().isUnprocessableEntity())
+                .andExpect(jsonPath("$.code").value(42204))
+                .andExpect(jsonPath("$.message").value("不能关注自己"));
+        // DELETE stays a plain idempotent no-op — the row cannot exist
+        mockMvc.perform(authed(delete("/api/v1/users/" + user + "/follow"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.following").value(false));
+    }
+
+    @Test
+    void absentOrCancelledTargetAnswers40406OnEveryPath() throws Exception {
+        UUID caller = newUser();
+        UUID ghost = UUID.randomUUID();
+        UUID cancelled = newUser();
+        jdbcClient.sql("UPDATE identity.users SET status = 'deleted', deleted_at = now()"
+                        + " WHERE id = :id")
+                .param("id", cancelled)
+                .update();
+
+        for (UUID target : List.of(ghost, cancelled)) {
+            mockMvc.perform(authed(put("/api/v1/users/" + target + "/follow"), caller))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40406));
+            mockMvc.perform(authed(delete("/api/v1/users/" + target + "/follow"), caller))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40406));
+            mockMvc.perform(authed(get("/api/v1/users/" + target + "/follow-stats"), caller))
+                    .andExpect(status().isNotFound())
+                    .andExpect(jsonPath("$.code").value(40406));
+        }
+        mockMvc.perform(authed(put("/api/v1/users/不是UUID/follow"), caller))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void followStatsCountBothDirectionsWithViewerFlag() throws Exception {
+        UUID alice = newUser();
+        UUID bob = newUser();
+        UUID carol = newUser();
+        // alice→bob, carol→bob, bob→alice
+        mockMvc.perform(authed(put("/api/v1/users/" + bob + "/follow"), alice))
+                .andExpect(status().isOk());
+        mockMvc.perform(authed(put("/api/v1/users/" + bob + "/follow"), carol))
+                .andExpect(status().isOk());
+        mockMvc.perform(authed(put("/api/v1/users/" + alice + "/follow"), bob))
+                .andExpect(status().isOk());
+
+        mockMvc.perform(authed(get("/api/v1/users/" + bob + "/follow-stats"), alice))
+                .andExpect(jsonPath("$.data.followerCount").value(2))
+                .andExpect(jsonPath("$.data.followingCount").value(1))
+                .andExpect(jsonPath("$.data.followedByMe").value(true));
+        mockMvc.perform(authed(get("/api/v1/users/" + alice + "/follow-stats"), carol))
+                .andExpect(jsonPath("$.data.followerCount").value(1))
+                .andExpect(jsonPath("$.data.followingCount").value(1))
+                .andExpect(jsonPath("$.data.followedByMe").value(false));
+        // asking about oneself: followedByMe is definitionally false
+        mockMvc.perform(authed(get("/api/v1/users/" + bob + "/follow-stats"), bob))
+                .andExpect(jsonPath("$.data.followerCount").value(2))
+                .andExpect(jsonPath("$.data.followedByMe").value(false));
+    }
+
+    @Test
+    void concurrentDuplicateFollowsLandExactlyOneRow() throws Exception {
+        UUID follower = newUser();
+        UUID target = newUser();
+        CountDownLatch start = new CountDownLatch(1);
+        ExecutorService pool = Executors.newFixedThreadPool(3);
+        try {
+            List<Future<Integer>> results = new ArrayList<>();
+            for (int i = 0; i < 3; i++) {
+                results.add(pool.submit(() -> {
+                    start.await();
+                    return mockMvc.perform(
+                                    authed(put("/api/v1/users/" + target + "/follow"), follower))
+                            .andReturn().getResponse().getStatus();
+                }));
+            }
+            start.countDown();
+            for (Future<Integer> result : results) {
+                assertThat(result.get(30, TimeUnit.SECONDS)).isEqualTo(200);
+            }
+        } finally {
+            pool.shutdownNow();
+        }
+        assertThat(followRows(target)).isEqualTo(1);
+        mockMvc.perform(authed(get("/api/v1/users/" + target + "/follow-stats"), follower))
+                .andExpect(jsonPath("$.data.followerCount").value(1));
+    }
+
+    private long followRows(UUID followee) {
+        return jdbcClient.sql("""
+                        SELECT count(*) FROM community.user_follows
+                        WHERE followee_user_id = :id
+                        """)
+                .param("id", followee)
+                .query(Long.class)
+                .single();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/interaction/LikeBookmarkIntegrationTest.java

@@ -0,0 +1,295 @@
+package com.patbond.patbond.community.interaction;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.patbond.patbond.community.post.PostApiTestBase;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.servlet.MvcResult;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * T3-06 idempotent like/bookmark on the real database: the authoritative
+ * terminal-state responses, TRUE concurrent convergence on the composite
+ * primary key (the M3 acceptance criterion: N concurrent PUTs count
+ * exactly 1), the 40403 interaction gate, the my-bookmarks keyset list
+ * with silent removal, and column-vs-relation reconciliation.
+ */
+class LikeBookmarkIntegrationTest extends PostApiTestBase {
+
+    @Test
+    void likeLifecycleIsIdempotentWithAuthoritativeState() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.liked").value(true))
+                .andExpect(jsonPath("$.data.likeCount").value(1));
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.liked").value(true))
+                .andExpect(jsonPath("$.data.likeCount").value(1));
+        assertThat(likeRows(postId)).isEqualTo(1);
+
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/like"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.liked").value(false))
+                .andExpect(jsonPath("$.data.likeCount").value(0));
+        // cancelling a like that does not exist neither errors nor
+        // decrements (工单验收)
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/like"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.liked").value(false))
+                .andExpect(jsonPath("$.data.likeCount").value(0));
+        assertThat(likeRows(postId)).isEqualTo(0);
+    }
+
+    @Test
+    void bookmarkLifecycleIsIdempotentWithAuthoritativeState() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/bookmark"), user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.bookmarked").value(true))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(1));
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/bookmark"), user))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(1));
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/bookmark"), user))
+                .andExpect(jsonPath("$.data.bookmarked").value(false))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(0));
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/bookmark"), user))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(0));
+    }
+
+    @Test
+    void distinctUsersAccumulateAndSurfaceInDetail() throws Exception {
+        UUID author = newUser();
+        UUID other = newUser();
+        String postId = publishPost(author);
+
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), author))
+                .andExpect(jsonPath("$.data.likeCount").value(1));
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), other))
+                .andExpect(jsonPath("$.data.likeCount").value(2));
+        mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/bookmark"), other))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(1));
+
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId), other))
+                .andExpect(jsonPath("$.data.likeCount").value(2))
+                .andExpect(jsonPath("$.data.bookmarkCount").value(1))
+                .andExpect(jsonPath("$.data.likedByMe").value(true))
+                .andExpect(jsonPath("$.data.bookmarkedByMe").value(true));
+        mockMvc.perform(authed(get("/api/v1/posts/" + postId), author))
+                .andExpect(jsonPath("$.data.likedByMe").value(true))
+                .andExpect(jsonPath("$.data.bookmarkedByMe").value(false));
+    }
+
+    @Test
+    void interactionsOnInvisiblePostsAnswerIdentical40403() throws Exception {
+        UUID author = newUser();
+        String ownDraft = createPost(author, "{\"content\": \"草稿\"}").get("id").asText();
+        String hidden = publishPost(author);
+        jdbcClient.sql("UPDATE community.posts SET status = 'hidden' WHERE id = :id")
+                .param("id", UUID.fromString(hidden))
+                .update();
+        String deleted = publishPost(author);
+        mockMvc.perform(authed(delete("/api/v1/posts/" + deleted), author))
+                .andExpect(status().isOk());
+
+        Set<String> bodies = new LinkedHashSet<>();
+        for (String target : List.of(ownDraft, hidden, deleted, UUID.randomUUID().toString())) {
+            for (String action : List.of("like", "bookmark")) {
+                MvcResult puts = mockMvc.perform(
+                                authed(put("/api/v1/posts/" + target + "/" + action), author))
+                        .andExpect(status().isNotFound())
+                        .andExpect(jsonPath("$.code").value(40403))
+                        .andReturn();
+                MvcResult deletes = mockMvc.perform(
+                                authed(delete("/api/v1/posts/" + target + "/" + action), author))
+                        .andExpect(status().isNotFound())
+                        .andExpect(jsonPath("$.code").value(40403))
+                        .andReturn();
+                bodies.add(puts.getResponse().getContentAsString());
+                bodies.add(deletes.getResponse().getContentAsString());
+            }
+        }
+        assertThat(bodies).hasSize(1);
+    }
+
+    @Test
+    void concurrentDuplicatePutsCountExactlyOne() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        CountDownLatch start = new CountDownLatch(1);
+        ExecutorService pool = Executors.newFixedThreadPool(4);
+        try {
+            List<Future<Integer>> results = new ArrayList<>();
+            for (int i = 0; i < 4; i++) {
+                results.add(pool.submit(() -> {
+                    start.await();
+                    return mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), user))
+                            .andReturn().getResponse().getStatus();
+                }));
+            }
+            start.countDown();
+            for (Future<Integer> result : results) {
+                assertThat(result.get(30, TimeUnit.SECONDS)).isEqualTo(200);
+            }
+        } finally {
+            pool.shutdownNow();
+        }
+        assertThat(likeRows(postId)).isEqualTo(1);
+        assertThat(likeColumn(postId)).isEqualTo(1);
+    }
+
+    @Test
+    void concurrentPutAndDeleteConvergeOnConsistentTerminalState() throws Exception {
+        UUID user = newUser();
+        String postId = publishPost(user);
+        CountDownLatch start = new CountDownLatch(1);
+        ExecutorService pool = Executors.newFixedThreadPool(2);
+        try {
+            Future<Integer> putting = pool.submit(() -> {
+                start.await();
+                return mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), user))
+                        .andReturn().getResponse().getStatus();
+            });
+            Future<Integer> deleting = pool.submit(() -> {
+                start.await();
+                return mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/like"), user))
+                        .andReturn().getResponse().getStatus();
+            });
+            start.countDown();
+            assertThat(putting.get(30, TimeUnit.SECONDS)).isEqualTo(200);
+            assertThat(deleting.get(30, TimeUnit.SECONDS)).isEqualTo(200);
+        } finally {
+            pool.shutdownNow();
+        }
+        // whichever order the race resolved in, the column agrees with the
+        // relation table — never a phantom count
+        assertThat(likeColumn(postId)).isEqualTo(likeRows(postId));
+    }
+
+    @Test
+    void countColumnsReconcileWithRelationRowsAfterMixedOps() throws Exception {
+        UUID author = newUser();
+        UUID second = newUser();
+        UUID third = newUser();
+        String postId = publishPost(author);
+        for (UUID user : List.of(author, second, third)) {
+            mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/like"), user))
+                    .andExpect(status().isOk());
+            mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/bookmark"), user))
+                    .andExpect(status().isOk());
+        }
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/like"), second))
+                .andExpect(status().isOk());
+        mockMvc.perform(authed(delete("/api/v1/posts/" + postId + "/bookmark"), third))
+                .andExpect(status().isOk());
+
+        assertThat(likeColumn(postId)).isEqualTo(2).isEqualTo(likeRows(postId));
+        long bookmarkColumn = jdbcClient.sql(
+                        "SELECT bookmark_count FROM community.posts WHERE id = :id")
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+        long bookmarkRows = jdbcClient.sql(
+                        "SELECT count(*) FROM community.post_bookmarks WHERE post_id = :id")
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+        assertThat(bookmarkColumn).isEqualTo(2).isEqualTo(bookmarkRows);
+    }
+
+    @Test
+    void myBookmarksPagesByBookmarkTimeAndDropsInvisible() throws Exception {
+        UUID author = newUser();
+        UUID reader = newUser();
+        List<String> posts = new ArrayList<>();
+        for (int i = 0; i < 5; i++) {
+            posts.add(publishPost(author));
+        }
+        for (String postId : posts) {
+            mockMvc.perform(authed(put("/api/v1/posts/" + postId + "/bookmark"), reader))
+                    .andExpect(status().isOk());
+        }
+        // one bookmarked post soft-deleted, one hidden → silently dropped
+        mockMvc.perform(authed(delete("/api/v1/posts/" + posts.get(1)), author))
+                .andExpect(status().isOk());
+        jdbcClient.sql("UPDATE community.posts SET status = 'hidden' WHERE id = :id")
+                .param("id", UUID.fromString(posts.get(3)))
+                .update();
+
+        List<String> seen = new ArrayList<>();
+        String cursor = null;
+        for (int page = 0; page < 3; page++) {
+            String url = "/api/v1/me/bookmarks?limit=2"
+                    + (cursor == null ? "" : "&cursor=" + cursor);
+            JsonNode body = data(mockMvc.perform(authed(get(url), reader))
+                    .andExpect(status().isOk())
+                    .andReturn());
+            for (JsonNode item : body.get("items")) {
+                seen.add(item.get("id").asText());
+                // the item IS the feed card: cover-less text post, counts,
+                // viewer flags, non-null publishedAt
+                assertThat(item.get("bookmarkedByMe").asBoolean()).isTrue();
+                assertThat(item.get("publishedAt").isNull()).isFalse();
+                assertThat(item.has("contentPreview")).isTrue();
+                assertThat(item.has("content")).isFalse();
+            }
+            if (!body.get("hasMore").asBoolean()) {
+                break;
+            }
+            cursor = body.get("nextCursor").asText();
+        }
+        // bookmark order DESC (posts were bookmarked 0→4), invisible dropped
+        assertThat(seen).containsExactly(posts.get(4), posts.get(2), posts.get(0));
+    }
+
+    @Test
+    void myBookmarksRejectsBadPagingInput() throws Exception {
+        UUID user = newUser();
+        mockMvc.perform(authed(get("/api/v1/me/bookmarks?limit=101"), user))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(authed(get("/api/v1/me/bookmarks?cursor=损坏"), user))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    private String publishPost(UUID author) throws Exception {
+        return createPost(author, "{\"content\": \"被互动的帖子\", \"status\": \"published\"}")
+                .get("id").asText();
+    }
+
+    private long likeRows(String postId) {
+        return jdbcClient.sql("SELECT count(*) FROM community.post_likes WHERE post_id = :id")
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+    }
+
+    private long likeColumn(String postId) {
+        return jdbcClient.sql("SELECT like_count FROM community.posts WHERE id = :id")
+                .param("id", UUID.fromString(postId))
+                .query(Long.class)
+                .single();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/post/AuthorProfileIntegrationTest.java

@@ -0,0 +1,150 @@
+package com.patbond.patbond.community.post;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.patbond.patbond.community.support.CommunityTestData;
+import com.patbond.patbond.community.support.StubAuthorProfileClient;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.web.servlet.MvcResult;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * AuthorSummary 定型 (D3-9 方案 B / T3-05): the detail response's author
+ * backfill (closes T3-04 contract deviation #1), the server-side
+ * nickname→username fallback, avatar URL signing, the short-TTL cache and
+ * the degrade-don't-5xx semantics when the user service is unreachable.
+ * The Feign transport itself is covered by AuthorProfileClientWireTest.
+ */
+class AuthorProfileIntegrationTest extends PostApiTestBase {
+
+    @Autowired
+    private StubAuthorProfileClient stubClient;
+
+    @AfterEach
+    void restoreUserService() {
+        stubClient.setUnavailable(false);
+    }
+
+    private JsonNode detail(UUID viewer, String postId) throws Exception {
+        MvcResult result = mockMvc.perform(authed(get("/api/v1/posts/" + postId), viewer))
+                .andExpect(status().isOk())
+                .andReturn();
+        return data(result);
+    }
+
+    @Test
+    void detailBackfillsTheAuthorSummaryWithTheNickname() throws Exception {
+        UUID author = newUser();
+        CommunityTestData.setNickname(jdbcClient, author, "毛毛的铲屎官");
+        JsonNode post = createPost(author, "{\"content\": \"作者摘要\", \"status\": \"published\"}");
+
+        JsonNode summary = detail(newUser(), post.get("id").asText()).get("author");
+        assertThat(summary.get("userId").asText()).isEqualTo(author.toString());
+        assertThat(summary.get("nickname").asText()).isEqualTo("毛毛的铲屎官");
+        assertThat(summary.get("avatarUrl").isNull()).isTrue();
+    }
+
+    @Test
+    void nicknameFallsBackToUsernameServerSide() throws Exception {
+        UUID author = newUser();
+        String username = jdbcClient.sql("SELECT username::text FROM identity.users WHERE id = :id")
+                .param("id", author)
+                .query(String.class)
+                .single();
+        JsonNode post = createPost(author, "{\"content\": \"回退昵称\", \"status\": \"published\"}");
+
+        JsonNode summary = detail(newUser(), post.get("id").asText()).get("author");
+        assertThat(summary.get("nickname").asText()).isEqualTo(username);
+    }
+
+    @Test
+    void readyAvatarBecomesASignedUrlAndUnreadyStaysNull() throws Exception {
+        UUID withReady = newUser();
+        UUID readyAsset = CommunityTestData.attachAvatar(jdbcClient, withReady, "ready");
+        UUID withUploading = newUser();
+        CommunityTestData.attachAvatar(jdbcClient, withUploading, "uploading");
+        JsonNode readyPost = createPost(withReady, "{\"content\": \"有头像\", \"status\": \"published\"}");
+        JsonNode uploadingPost = createPost(withUploading, "{\"content\": \"头像未就绪\", \"status\": \"published\"}");
+
+        UUID viewer = newUser();
+        JsonNode readySummary = detail(viewer, readyPost.get("id").asText()).get("author");
+        assertThat(readySummary.get("avatarUrl").asText())
+                .contains(readyAsset.toString())
+                .contains("X-Amz-Signature");
+        JsonNode uploadingSummary = detail(viewer, uploadingPost.get("id").asText()).get("author");
+        assertThat(uploadingSummary.get("avatarUrl").isNull()).isTrue();
+    }
+
+    @Test
+    void secondLookupWithinTheTtlIsServedFromTheCache() throws Exception {
+        UUID author = newUser();
+        UUID postId = CommunityTestData.insertPublishedPost(jdbcClient, author, "缓存命中");
+        UUID viewer = newUser();
+
+        int before = stubClient.invocationCount();
+        detail(viewer, postId.toString());
+        int afterFirst = stubClient.invocationCount();
+        detail(viewer, postId.toString());
+        int afterSecond = stubClient.invocationCount();
+
+        assertThat(afterFirst - before).isEqualTo(1);
+        assertThat(afterSecond - afterFirst).isZero();
+    }
+
+    @Test
+    void unreachableUserServiceDegradesToIdOnlyInsteadOf5xx() throws Exception {
+        UUID author = newUser();
+        CommunityTestData.setNickname(jdbcClient, author, "看不见的昵称");
+        UUID postId = CommunityTestData.insertPublishedPost(jdbcClient, author, "降级帖");
+
+        stubClient.setUnavailable(true);
+        JsonNode summary = detail(newUser(), postId.toString()).get("author");
+        assertThat(summary.get("userId").asText()).isEqualTo(author.toString());
+        assertThat(summary.get("nickname").isNull()).isTrue();
+        assertThat(summary.get("avatarUrl").isNull()).isTrue();
+    }
+
+    @Test
+    void degradedFeedStillServesEveryCard() throws Exception {
+        UUID author = newUser();
+        UUID postId = CommunityTestData.insertPublishedPost(jdbcClient, author, "降级 Feed");
+
+        stubClient.setUnavailable(true);
+        MvcResult result = mockMvc.perform(
+                        authed(get("/api/v1/feed").queryParam("limit", "100"), newUser()))
+                .andExpect(status().isOk())
+                .andReturn();
+        JsonNode items = data(result).get("items");
+        JsonNode card = null;
+        for (JsonNode item : items) {
+            if (item.get("id").asText().equals(postId.toString())) {
+                card = item;
+            }
+        }
+        assertThat(card).isNotNull();
+        assertThat(card.get("author").get("userId").asText()).isEqualTo(author.toString());
+        assertThat(card.get("author").get("nickname").isNull()).isTrue();
+    }
+
+    @Test
+    void aFailedLookupIsNotCachedSoTheNextRequestRecovers() throws Exception {
+        UUID author = newUser();
+        CommunityTestData.setNickname(jdbcClient, author, "恢复后的昵称");
+        UUID postId = CommunityTestData.insertPublishedPost(jdbcClient, author, "降级不缓存");
+        UUID viewer = newUser();
+
+        stubClient.setUnavailable(true);
+        JsonNode degraded = detail(viewer, postId.toString()).get("author");
+        assertThat(degraded.get("nickname").isNull()).isTrue();
+
+        stubClient.setUnavailable(false);
+        JsonNode recovered = detail(viewer, postId.toString()).get("author");
+        assertThat(recovered.get("nickname").asText()).isEqualTo("恢复后的昵称");
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/post/FeedCardIntegrationTest.java

@@ -0,0 +1,133 @@
+package com.patbond.patbond.community.post;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.patbond.patbond.community.support.CommunityTestData;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.servlet.MvcResult;
+
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Feed card field 定型 (T3-05, the FeedCard freeze input): the 200-code-point
+ * preview rule, cover selection from the unique is_cover row, mediaCount,
+ * counts read from the posts table's denormalized columns, and the
+ * viewer-relative flags.
+ */
+class FeedCardIntegrationTest extends PostApiTestBase {
+
+    private UUID viewer;
+
+    @BeforeEach
+    void wipeFeed() {
+        jdbcClient.sql("DELETE FROM community.posts").update();
+        viewer = newUser();
+    }
+
+    private JsonNode firstCard() throws Exception {
+        MvcResult result = mockMvc.perform(authed(get("/api/v1/feed"), viewer))
+                .andExpect(status().isOk())
+                .andReturn();
+        JsonNode items = data(result).get("items");
+        assertThat(items).hasSize(1);
+        return items.get(0);
+    }
+
+    @Test
+    void cardCarriesTheFrozenFieldSetForATextOnlyPost() throws Exception {
+        UUID author = newUser();
+        JsonNode post = createPost(author, """
+                {"title": "卡片字段", "content": "纯文字帖", "category": "help",
+                 "status": "published"}
+                """);
+
+        JsonNode card = firstCard();
+        assertThat(card.get("id").asText()).isEqualTo(post.get("id").asText());
+        assertThat(card.get("author").get("userId").asText()).isEqualTo(author.toString());
+        assertThat(card.get("category").asText()).isEqualTo("help");
+        assertThat(card.get("title").asText()).isEqualTo("卡片字段");
+        assertThat(card.get("contentPreview").asText()).isEqualTo("纯文字帖");
+        assertThat(card.get("coverImage").isNull()).isTrue();
+        assertThat(card.get("mediaCount").asInt()).isZero();
+        assertThat(card.get("likeCount").asLong()).isZero();
+        assertThat(card.get("commentCount").asLong()).isZero();
+        assertThat(card.get("bookmarkCount").asLong()).isZero();
+        assertThat(card.get("likedByMe").asBoolean()).isFalse();
+        assertThat(card.get("bookmarkedByMe").asBoolean()).isFalse();
+        assertThat(card.get("publishedAt").asText()).contains("T");
+        // Trimmed relative to Post: no full content, no version, no visibility.
+        assertThat(card.has("content")).isFalse();
+        assertThat(card.has("version")).isFalse();
+    }
+
+    @Test
+    void previewCutsAtTwoHundredCodePointsWithoutSplittingSurrogates() throws Exception {
+        UUID author = newUser();
+        String content = "汉".repeat(199) + "🐱" + "这些字符必须被截掉";
+        createPost(author,
+                "{\"content\": \"%s\", \"status\": \"published\"}".formatted(content));
+
+        String preview = firstCard().get("contentPreview").asText();
+        assertThat(preview.codePointCount(0, preview.length())).isEqualTo(200);
+        assertThat(preview).isEqualTo("汉".repeat(199) + "🐱");
+    }
+
+    @Test
+    void shortContentIsPassedThroughVerbatim() throws Exception {
+        UUID author = newUser();
+        createPost(author, "{\"content\": \"刚好不截断\", \"status\": \"published\"}");
+        assertThat(firstCard().get("contentPreview").asText()).isEqualTo("刚好不截断");
+    }
+
+    @Test
+    void coverIsTheIsCoverRowAndMediaCountTheWholeSet() throws Exception {
+        UUID author = newUser();
+        UUID assetA = CommunityTestData.insertReadyAsset(jdbcClient, author);
+        UUID assetB = CommunityTestData.insertReadyAsset(jdbcClient, author);
+        createPost(author, """
+                {"content": "两图帖", "status": "published",
+                 "media": [{"assetId": "%s"}, {"assetId": "%s", "isCover": true}]}
+                """.formatted(assetA, assetB));
+
+        JsonNode card = firstCard();
+        assertThat(card.get("mediaCount").asInt()).isEqualTo(2);
+        JsonNode cover = card.get("coverImage");
+        assertThat(cover.get("assetId").asText()).isEqualTo(assetB.toString());
+        assertThat(cover.get("isCover").asBoolean()).isTrue();
+        assertThat(cover.get("url").asText())
+                .contains(assetB.toString())
+                .contains("X-Amz-Signature");
+    }
+
+    @Test
+    void countsComeFromTheDenormalizedColumnsAndFlagsFromTheRelationTables() throws Exception {
+        UUID author = newUser();
+        JsonNode post = createPost(author, "{\"content\": \"计数帖\", \"status\": \"published\"}");
+        UUID postId = UUID.fromString(post.get("id").asText());
+        jdbcClient.sql("""
+                        UPDATE community.posts
+                        SET like_count = 5, comment_count = 3, bookmark_count = 2
+                        WHERE id = :id
+                        """)
+                .param("id", postId)
+                .update();
+        jdbcClient.sql("""
+                        INSERT INTO community.post_likes (post_id, user_id)
+                        VALUES (:postId, :userId)
+                        """)
+                .param("postId", postId)
+                .param("userId", viewer)
+                .update();
+
+        JsonNode card = firstCard();
+        assertThat(card.get("likeCount").asLong()).isEqualTo(5);
+        assertThat(card.get("commentCount").asLong()).isEqualTo(3);
+        assertThat(card.get("bookmarkCount").asLong()).isEqualTo(2);
+        assertThat(card.get("likedByMe").asBoolean()).isTrue();
+        assertThat(card.get("bookmarkedByMe").asBoolean()).isFalse();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/post/FeedPaginationIntegrationTest.java

@@ -0,0 +1,207 @@
+package com.patbond.patbond.community.post;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
+
+import java.time.OffsetDateTime;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Feed pagination 专项 (T3-05 工单要求): empty feed, single page, page
+ * walking with no loss and no duplication (including published_at ties and
+ * inserts/deletes between page fetches), cursor validity, and the
+ * visibility predicate. The feed is global state, so every test starts
+ * from a wiped community.posts (the FK cascades clear media/likes/
+ * bookmarks); other test classes create their own rows per test and run
+ * sequentially, so the wipe races nothing.
+ */
+class FeedPaginationIntegrationTest extends PostApiTestBase {
+
+    private UUID viewer;
+
+    @BeforeEach
+    void wipeFeed() {
+        jdbcClient.sql("DELETE FROM community.posts").update();
+        viewer = newUser();
+    }
+
+    private MockHttpServletRequestBuilder feed(UUID userId, Integer limit, String cursor) {
+        MockHttpServletRequestBuilder builder = authed(get("/api/v1/feed"), userId);
+        if (limit != null) {
+            builder = builder.queryParam("limit", String.valueOf(limit));
+        }
+        if (cursor != null) {
+            builder = builder.queryParam("cursor", cursor);
+        }
+        return builder;
+    }
+
+    private JsonNode feedPage(UUID userId, Integer limit, String cursor) throws Exception {
+        MvcResult result = mockMvc.perform(feed(userId, limit, cursor))
+                .andExpect(status().isOk())
+                .andReturn();
+        return data(result);
+    }
+
+    private UUID publish(UUID author, String content) throws Exception {
+        JsonNode post = createPost(author,
+                "{\"content\": \"%s\", \"status\": \"published\"}".formatted(content));
+        return UUID.fromString(post.get("id").asText());
+    }
+
+    private List<String> idsOf(JsonNode page) {
+        List<String> ids = new ArrayList<>();
+        page.get("items").forEach(item -> ids.add(item.get("id").asText()));
+        return ids;
+    }
+
+    @Test
+    void emptyFeedIsAnEmptyPage() throws Exception {
+        JsonNode page = feedPage(viewer, null, null);
+        assertThat(page.get("items")).isEmpty();
+        assertThat(page.get("hasMore").asBoolean()).isFalse();
+        assertThat(page.get("nextCursor").isNull()).isTrue();
+    }
+
+    @Test
+    void singlePageListsNewestFirstWithoutACursor() throws Exception {
+        UUID author = newUser();
+        UUID first = publish(author, "一号帖");
+        UUID second = publish(author, "二号帖");
+
+        JsonNode page = feedPage(viewer, null, null);
+        assertThat(idsOf(page)).containsExactly(second.toString(), first.toString());
+        assertThat(page.get("hasMore").asBoolean()).isFalse();
+        assertThat(page.get("nextCursor").isNull()).isTrue();
+    }
+
+    @Test
+    void onlyLivePublishedPublicPostsAppear() throws Exception {
+        UUID author = newUser();
+        UUID visible = publish(author, "可见的帖子");
+        createPost(author, "{\"content\": \"草稿不进 Feed\"}");
+        UUID deleted = publish(author, "删除后不进 Feed");
+        mockMvc.perform(authed(delete("/api/v1/posts/" + deleted), author))
+                .andExpect(status().isOk());
+        UUID hidden = publish(author, "hidden 不进 Feed");
+        jdbcClient.sql("UPDATE community.posts SET status = 'hidden' WHERE id = :id")
+                .param("id", hidden)
+                .update();
+        UUID nonPublic = publish(author, "followers 可见性不进 Feed");
+        jdbcClient.sql("UPDATE community.posts SET visibility = 'followers' WHERE id = :id")
+                .param("id", nonPublic)
+                .update();
+
+        JsonNode page = feedPage(viewer, null, null);
+        assertThat(idsOf(page)).containsExactly(visible.toString());
+    }
+
+    @Test
+    void pageWalkLosesNothingAndRepeatsNothing() throws Exception {
+        UUID author = newUser();
+        List<String> published = new ArrayList<>();
+        for (int i = 0; i < 7; i++) {
+            published.add(publish(author, "翻页帖 " + i).toString());
+        }
+        List<String> expected = new ArrayList<>(published);
+        java.util.Collections.reverse(expected);
+
+        List<String> crawled = new ArrayList<>();
+        String cursor = null;
+        int pages = 0;
+        while (true) {
+            JsonNode page = feedPage(viewer, 3, cursor);
+            crawled.addAll(idsOf(page));
+            pages++;
+            if (!page.get("hasMore").asBoolean()) {
+                assertThat(page.get("nextCursor").isNull()).isTrue();
+                break;
+            }
+            cursor = page.get("nextCursor").asText();
+        }
+        assertThat(pages).isEqualTo(3);
+        assertThat(crawled).containsExactlyElementsOf(expected);
+    }
+
+    @Test
+    void publishedAtTiesAreBrokenByIdWithoutLossOrDuplication() throws Exception {
+        UUID author = newUser();
+        List<UUID> ids = new ArrayList<>();
+        for (int i = 0; i < 3; i++) {
+            ids.add(publish(author, "同刻帖 " + i));
+        }
+        OffsetDateTime sameInstant = OffsetDateTime.now();
+        for (UUID id : ids) {
+            jdbcClient.sql("UPDATE community.posts SET published_at = :ts WHERE id = :id")
+                    .param("ts", sameInstant)
+                    .param("id", id)
+                    .update();
+        }
+        List<String> expected = ids.stream()
+                .map(UUID::toString)
+                .sorted(java.util.Comparator.reverseOrder())
+                .toList();
+
+        JsonNode page1 = feedPage(viewer, 2, null);
+        JsonNode page2 = feedPage(viewer, 2, page1.get("nextCursor").asText());
+        List<String> crawled = new ArrayList<>(idsOf(page1));
+        crawled.addAll(idsOf(page2));
+        assertThat(crawled).containsExactlyElementsOf(expected);
+        assertThat(page2.get("hasMore").asBoolean()).isFalse();
+    }
+
+    @Test
+    void insertsAndDeletesBetweenPagesNeitherShiftNorRepeat() throws Exception {
+        UUID author = newUser();
+        List<UUID> ids = new ArrayList<>();
+        for (int i = 0; i < 5; i++) {
+            ids.add(publish(author, "间隙帖 " + i));
+        }
+        // Oldest→newest is ids[0..4]; page 1 (limit 2) shows ids[4], ids[3].
+        JsonNode page1 = feedPage(viewer, 2, null);
+        assertThat(idsOf(page1)).containsExactly(ids.get(4).toString(), ids.get(3).toString());
+
+        // Between the fetches: a new post lands (newer than the cursor — must
+        // NOT shift page 2) and one page-2 candidate is deleted (must vanish
+        // without repeating anything).
+        publish(author, "翻页间隙新发布");
+        mockMvc.perform(authed(delete("/api/v1/posts/" + ids.get(2)), author))
+                .andExpect(status().isOk());
+
+        JsonNode page2 = feedPage(viewer, 2, page1.get("nextCursor").asText());
+        assertThat(idsOf(page2)).containsExactly(ids.get(1).toString(), ids.get(0).toString());
+        assertThat(page2.get("hasMore").asBoolean()).isFalse();
+    }
+
+    @Test
+    void invalidCursorsAreA400() throws Exception {
+        mockMvc.perform(feed(viewer, null, "not-base64url!!"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(feed(viewer, null,
+                java.util.Base64.getUrlEncoder().encodeToString("garbage".getBytes())))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void limitOutOfBoundsIsA400() throws Exception {
+        mockMvc.perform(feed(viewer, 0, null))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(feed(viewer, 101, null))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/post/PostApiTestBase.java

@@ -4,6 +4,7 @@ import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.patbond.patbond.community.TestcontainersConfiguration;
 import com.patbond.patbond.community.support.CommunityTestData;
+import com.patbond.patbond.community.support.StubAuthorProfileConfig;
 import com.patbond.patbond.community.support.TestJwtKeys;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
@@ -32,7 +33,7 @@ import static org.springframework.test.web.servlet.request.MockMvcRequestBuilder
  */
 @SpringBootTest
 @AutoConfigureMockMvc
-@Import(TestcontainersConfiguration.class)
+@Import({TestcontainersConfiguration.class, StubAuthorProfileConfig.class})
 public abstract class PostApiTestBase {
 
     @Autowired

patbond-community/src/test/java/com/patbond/patbond/community/post/PostLifecycleIntegrationTest.java

@@ -38,7 +38,7 @@ class PostLifecycleIntegrationTest extends PostApiTestBase {
                 .andExpect(status().isCreated())
                 .andExpect(jsonPath("$.code").value(0))
                 .andExpect(jsonPath("$.data.id").isNotEmpty())
-                .andExpect(jsonPath("$.data.authorId").value(author.toString()))
+                .andExpect(jsonPath("$.data.author.userId").value(author.toString()))
                 .andExpect(jsonPath("$.data.title").value("第一帖"))
                 .andExpect(jsonPath("$.data.content").value("大家好"))
                 .andExpect(jsonPath("$.data.category").value("general"))

patbond-community/src/test/java/com/patbond/patbond/community/support/CommunityTestData.java

@@ -25,6 +25,23 @@ public final class CommunityTestData {
         return id;
     }
 
+    public static void setNickname(JdbcClient jdbc, UUID userId, String nickname) {
+        jdbc.sql("UPDATE identity.users SET nickname = :nickname WHERE id = :id")
+                .param("nickname", nickname)
+                .param("id", userId)
+                .update();
+    }
+
+    /** Gives the user an avatar asset in the given status; returns the asset id. */
+    public static UUID attachAvatar(JdbcClient jdbc, UUID userId, String status) {
+        UUID assetId = insertAsset(jdbc, userId, status);
+        jdbc.sql("UPDATE identity.users SET avatar_asset_id = :assetId WHERE id = :id")
+                .param("assetId", assetId)
+                .param("id", userId)
+                .update();
+        return assetId;
+    }
+
     /** One ready image asset owned by the given user, as T3-03 would leave it. */
     public static UUID insertReadyAsset(JdbcClient jdbc, UUID ownerUserId) {
         return insertAsset(jdbc, ownerUserId, "ready");
@@ -48,6 +65,24 @@ public final class CommunityTestData {
         return id;
     }
 
+    /**
+     * A published post inserted straight into community.posts — used when a
+     * test must NOT go through the create API (whose response assembly
+     * would already resolve and cache the author's profile).
+     */
+    public static UUID insertPublishedPost(JdbcClient jdbc, UUID authorUserId, String content) {
+        UUID id = UuidV7.generate();
+        jdbc.sql("""
+                        INSERT INTO community.posts (id, author_user_id, content, status, published_at)
+                        VALUES (:id, :author, :content, 'published', now())
+                        """)
+                .param("id", id)
+                .param("author", authorUserId)
+                .param("content", content)
+                .update();
+        return id;
+    }
+
     public static UUID insertPetOwnedBy(JdbcClient jdbc, UUID ownerUserId) {
         UUID id = UuidV7.generate();
         jdbc.sql("""

patbond-community/src/test/java/com/patbond/patbond/community/support/StubAuthorProfileClient.java

@@ -0,0 +1,61 @@
+package com.patbond.patbond.community.support;
+
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.community.author.AuthorProfileClient;
+import com.patbond.patbond.community.author.AuthorProfileDto;
+import org.springframework.jdbc.core.simple.JdbcClient;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * In-process stand-in for patbond-user's /internal/users/profiles, wired in
+ * place of the Feign proxy (工单许可：Feign 层用替身，/internal 端点自身在
+ * patbond-user 模块测全；两服务同 JVM 的 AuthE2e 先例成本过高)。 It answers
+ * from identity.users with the same query the real endpoint runs — including
+ * the nickname→username fallback — so profile tests seed users exactly like
+ * every other cross-schema fixture. {@link #unavailable} simulates the user
+ * service being down (the gateway must degrade, not 5xx);
+ * {@link #invocations} makes the cache observable.
+ */
+public class StubAuthorProfileClient implements AuthorProfileClient {
+
+    private final JdbcClient jdbcClient;
+    private final AtomicInteger invocations = new AtomicInteger();
+    private volatile boolean unavailable;
+
+    public StubAuthorProfileClient(JdbcClient jdbcClient) {
+        this.jdbcClient = jdbcClient;
+    }
+
+    @Override
+    public ApiResponse<List<AuthorProfileDto>> profiles(String ids) {
+        invocations.incrementAndGet();
+        if (unavailable) {
+            throw new IllegalStateException("stub: user service unavailable");
+        }
+        List<UUID> parsed = Arrays.stream(ids.split(",")).map(UUID::fromString).toList();
+        List<AuthorProfileDto> profiles = jdbcClient.sql("""
+                        SELECT id, COALESCE(nickname, username::text) AS nickname, avatar_asset_id
+                        FROM identity.users
+                        WHERE id IN (:ids) AND deleted_at IS NULL
+                        """)
+                .param("ids", parsed)
+                .query((rs, rowNum) -> new AuthorProfileDto(
+                        rs.getObject("id", UUID.class),
+                        rs.getString("nickname"),
+                        rs.getObject("avatar_asset_id", UUID.class)))
+                .list();
+        return ApiResponse.success(profiles);
+    }
+
+    public void setUnavailable(boolean value) {
+        this.unavailable = value;
+    }
+
+    public int invocationCount() {
+        return invocations.get();
+    }
+}

patbond-community/src/test/java/com/patbond/patbond/community/support/StubAuthorProfileConfig.java

@@ -0,0 +1,22 @@
+package com.patbond.patbond.community.support;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Primary;
+import org.springframework.jdbc.core.simple.JdbcClient;
+
+/**
+ * Replaces the AuthorProfileClient Feign proxy with the DB-backed stub for
+ * the shared post/feed test context. The Feign machinery itself (URL, token
+ * interceptor, envelope decoding) is exercised separately by
+ * AuthorProfileClientWireTest against a real HTTP server.
+ */
+@TestConfiguration(proxyBeanMethods = false)
+public class StubAuthorProfileConfig {
+
+    @Bean
+    @Primary
+    public StubAuthorProfileClient stubAuthorProfileClient(JdbcClient jdbcClient) {
+        return new StubAuthorProfileClient(jdbcClient);
+    }
+}

patbond-community/src/test/resources/application.yml

@@ -4,3 +4,12 @@
 spring:
   application:
     name: patbond-community
+
+patbond:
+  # Feign client wiring must resolve at context start. Author-profile tests
+  # either replace the client bean with a DB-backed stub or (the wire test)
+  # override this URL with an in-test HTTP server; nothing ever calls this
+  # unroutable address.
+  user-service:
+    url: http://127.0.0.1:1
+  internal-token: test-internal-token

patbond-pet/src/test/java/com/patbond/patbond/pet/contract/ContractConformanceTest.java

@@ -27,8 +27,8 @@ import static org.springframework.test.web.servlet.request.MockMvcRequestBuilder
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.request;
 
 /**
- * T2-09 契约一致性保障：对冻结契约 v1.2.0（快照
- * {@code src/test/resources/contract/openapi-v1.2.0.yaml}，正典在 doc 仓
+ * T2-09 契约一致性保障：对冻结契约 v1.3.0（快照
+ * {@code src/test/resources/contract/openapi-v1.3.0.yaml}，正典在 doc 仓
  * {@code docs/api/openapi.yaml}）的 pets 域 18 个操作逐一真实起服务发请求，
  * 用 {@link ContractValidator} 严格校验响应结构：路径/方法/状态码已声明、
  * 字段名与类型、必填与 nullable、枚举与格式、信封结构、错误码值。
@@ -703,10 +703,10 @@ class ContractConformanceTest extends PetIntegrationTestSupport {
     @Test
     @Order(98)
     void frozenSnapshotIsTheExpectedContractVersion() {
-        assertThat(CONTRACT.version()).isEqualTo("1.2.0");
-        assertThat(CONTRACT.paths()).hasSize(18);
-        assertThat(CONTRACT.operations()).hasSize(24);
-        assertThat(CONTRACT.schemas()).hasSize(45);
+        assertThat(CONTRACT.version()).isEqualTo("1.3.0");
+        assertThat(CONTRACT.paths()).hasSize(31);
+        assertThat(CONTRACT.operations()).hasSize(43);
+        assertThat(CONTRACT.schemas()).hasSize(72);
         assertThat(CONTRACT.operationsTagged(Set.of("pets", "dictionaries", "health-records")))
                 .containsExactlyInAnyOrderElementsOf(PETS_OPERATIONS);
     }

patbond-pet/src/test/java/com/patbond/patbond/pet/contract/ContractValidator.java

@@ -10,6 +10,7 @@ import java.time.OffsetDateTime;
 import java.time.format.DateTimeParseException;
 import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -81,7 +82,7 @@ final class ContractValidator {
     }
 
     private void validate(Map<String, Object> rawSchema, JsonNode node, String loc, List<String> errors) {
-        Map<String, Object> schema = contract.resolve(rawSchema);
+        Map<String, Object> schema = effectiveSchema(rawSchema);
         if (node == null || node.isMissingNode()) {
             errors.add(loc + ": 字段缺失");
             return;
@@ -130,6 +131,32 @@ final class ContractValidator {
         }
     }
 
+    /**
+     * Resolves $refs and flattens the v1.3.0 {@code nullable + allOf: [$ref]}
+     * pattern into one plain schema (branch keys first, sibling keys — e.g.
+     * the outer {@code nullable} — win). The frozen contract only ever uses
+     * single-branch allOf, so a shallow merge is exact; overlapping
+     * {@code properties} across branches would need a deep merge and are not
+     * supported.
+     */
+    private Map<String, Object> effectiveSchema(Map<String, Object> rawSchema) {
+        Map<String, Object> schema = contract.resolve(rawSchema);
+        List<Object> allOf = list(schema, "allOf");
+        if (allOf == null) {
+            return schema;
+        }
+        Map<String, Object> merged = new LinkedHashMap<>();
+        for (Object branch : allOf) {
+            merged.putAll(effectiveSchema(cast(branch)));
+        }
+        schema.forEach((key, value) -> {
+            if (!"allOf".equals(key)) {
+                merged.put(key, value);
+            }
+        });
+        return merged;
+    }
+
     private void validateObject(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
         if (!node.isObject()) {
             errors.add(loc + ": 应为 object，实际 " + node.getNodeType());

patbond-pet/src/test/java/com/patbond/patbond/pet/contract/OpenApiContract.java

@@ -13,8 +13,8 @@ import java.util.Objects;
 import java.util.Set;
 
 /**
- * The frozen v1.2.0 OpenAPI contract, loaded from the test-resource snapshot
- * {@code /contract/openapi-v1.2.0.yaml}.
+ * The frozen v1.3.0 OpenAPI contract, loaded from the test-resource snapshot
+ * {@code /contract/openapi-v1.3.0.yaml}.
  *
  * <p><b>Sync discipline (T2-09)</b>: the canonical contract lives in the doc
  * repo at {@code docs/api/openapi.yaml}; this snapshot is a byte-identical
@@ -26,11 +26,13 @@ import java.util.Set;
  *
  * <p>Only the subset of OpenAPI 3.0 this contract actually uses is supported:
  * local {@code #/} refs, plain types, {@code nullable}, {@code enum},
- * {@code required}, {@code properties}, {@code items} — no allOf/oneOf.
+ * {@code required}, {@code properties}, {@code items}, and the v1.3.0
+ * single-branch {@code nullable + allOf: [$ref]} pattern (merged in
+ * {@link ContractValidator}) — no oneOf/anyOf.
  */
 final class OpenApiContract {
 
-    static final String RESOURCE = "/contract/openapi-v1.2.0.yaml";
+    static final String RESOURCE = "/contract/openapi-v1.3.0.yaml";
 
     private static final Set<String> HTTP_METHODS =
             Set.of("get", "put", "post", "delete", "options", "head", "patch", "trace");

patbond-user/src/main/java/com/patbond/patbond/user/analytics/EventDictionary.java

@@ -5,20 +5,32 @@ import java.util.Set;
 import java.util.regex.Pattern;
 
 /**
- * Event dictionary v2 (report 06 §1.4/§1.5): v1 auth funnel (report 13 §4)
- * plus the M2 increment — pet domain (3 events) and health_record domain
- * (7 events) — and page_viewed formalized (report 06 §5.2, was report 19
- * ad-hoc addition; same props keys pageName/referrer).
+ * Event dictionary v3 (iteration-3 report 06 §1.4/§1.5, ADR-020): v1 auth
+ * funnel + v2 pet/health_record domains + page_viewed 正稿, plus the M3
+ * community increment — post domain (8: publish funnel, draft, delete, and
+ * the per-file media upload funnel), feed domain (2: feed_viewed as an
+ * aggregated browse-segment exposure event per §1.2 — no per-card
+ * post_impression — and feed_load_failed), interactions (8: like/unlike,
+ * favorite/unfavorite, comment success/failure pair, follow/unfollow) —
+ * and experiment_exposed (platform domain, A/B prerequisite #5, dictionary
+ * ahead of its M4 first use).
  * ADR-013: health_record_action removed (client zero-reference), replaced by
  * the per-action health_record_* events below.
  * Unknown event names reject the whole event; props outside the per-event
  * whitelist are stripped (kept event, counted warning); props whose KEY
  * matches the privacy red-line pattern (report 13 §5.2.4) reject the event.
+ * Community privacy red-lines (report 06 §1.3): no free text, no content or
+ * counterpart IDs (postId/commentId/topicId/target userId), no topic names,
+ * no file names/paths/URLs — only behavior counts and buckets
+ * (textLengthBucket, sizeBucket) ever reach props.
  * Value-level enum conformance (recordType: weight/vaccine/health_event/
- * reminder; failureReason incl. permission_denied/conflict/not_found;
- * pageName: login/register/home/profile/pet_list/pet_detail/pet_form/
- * record_form/record_detail) is enforced client-side (compile-time enums)
- * and patrolled offline (report 06 §6.4); ingest validates keys only.
+ * reminder; failureReason incl. media_too_large/unsupported_format;
+ * pageName v3 family: login/register/home/profile/pet_list/pet_detail/
+ * pet_form/record_form/record_detail + create/pet_archive/services/
+ * post_detail (收编) + post_form/topic_list/topic_detail/user_profile/
+ * follower_list/following_list/favorite_list/draft_list) is enforced
+ * client-side (compile-time enums) and patrolled offline (report 06 §6.4);
+ * ingest validates keys only — pageName growth needs no code change here.
  */
 public final class EventDictionary {
 
@@ -59,7 +71,36 @@ public final class EventDictionary {
             Map.entry("health_record_edit_succeeded", Set.of("recordType", "fieldCount")),
             Map.entry("health_record_edit_failed",
                     Set.of("recordType", "failureReason", "errorCode", "httpStatus")),
-            Map.entry("health_record_deleted", Set.of("recordType"))
+            Map.entry("health_record_deleted", Set.of("recordType")),
+            // v3 增量 post 域（iteration-3 报告 06 §1.4）
+            Map.entry("post_create_started", Set.of("entryPoint")),
+            Map.entry("post_draft_saved", Set.of("trigger", "mediaCount")),
+            Map.entry("post_publish_succeeded",
+                    Set.of("durationMs", "mediaCount", "topicCount", "textLengthBucket", "fromDraft")),
+            Map.entry("post_publish_failed",
+                    Set.of("failureReason", "errorCode", "httpStatus", "attemptSeq")),
+            Map.entry("post_deleted", Set.of()),
+            Map.entry("post_media_upload_started", Set.of("mediaType", "sizeBucket")),
+            Map.entry("post_media_upload_succeeded", Set.of("mediaType", "sizeBucket", "durationMs")),
+            Map.entry("post_media_upload_failed",
+                    Set.of("mediaType", "sizeBucket", "failureReason", "errorCode", "httpStatus", "attemptSeq")),
+            // v3 增量 feed 域（聚合曝光设计，§1.2 裁定）
+            Map.entry("feed_viewed",
+                    Set.of("feedTab", "durationMs", "impressionCount", "loadMoreCount", "refreshCount")),
+            Map.entry("feed_load_failed",
+                    Set.of("feedTab", "loadType", "failureReason", "errorCode", "httpStatus")),
+            // v3 增量互动
+            Map.entry("post_liked", Set.of("source")),
+            Map.entry("post_unliked", Set.of("source")),
+            Map.entry("post_favorited", Set.of("source")),
+            Map.entry("post_unfavorited", Set.of("source")),
+            Map.entry("comment_create_succeeded", Set.of("durationMs", "isReply", "textLengthBucket")),
+            Map.entry("comment_create_failed",
+                    Set.of("failureReason", "errorCode", "httpStatus", "attemptSeq")),
+            Map.entry("user_followed", Set.of("source")),
+            Map.entry("user_unfollowed", Set.of("source")),
+            // A/B 前置 #5：曝光事件字典先行，M4 启用（§1.4）
+            Map.entry("experiment_exposed", Set.of("experimentKey", "variant"))
     );
 
     public static boolean isKnownEvent(String eventName) {

patbond-user/src/main/java/com/patbond/patbond/user/controller/InternalProfileController.java

@@ -0,0 +1,77 @@
+package com.patbond.patbond.user.controller;
+
+import com.patbond.patbond.common.error.BusinessException;
+import com.patbond.patbond.common.error.ErrorCode;
+import com.patbond.patbond.common.response.ApiResponse;
+import com.patbond.patbond.user.dto.PublicProfileResponse;
+import com.patbond.patbond.user.repository.UserRepository;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * Internal batch public-profile API (D3-9 方案 B, T3-05), consumed by
+ * patbond-community for feed/comment author summaries. Guarded by
+ * InternalAuthFilter like every /internal/** route.
+ *
+ * <p>Semantics: {@code ids} is a mandatory comma-separated list of user ids,
+ * at most {@value #MAX_BATCH} per call (one feed page's worth of authors
+ * with headroom) — more is a 400, matching the batch-not-loop contract the
+ * consumer's cache is built around. Ids that do not resolve (unknown, or the
+ * user is soft-deleted) are silently absent from the reply; the caller
+ * renders its id-only fallback for them, so absence leaks nothing about
+ * which of the two cases it was.</p>
+ */
+@RestController
+@RequestMapping("/internal/users")
+public class InternalProfileController {
+
+    static final int MAX_BATCH = 50;
+
+    private final UserRepository userRepository;
+
+    public InternalProfileController(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    @GetMapping("/profiles")
+    public ApiResponse<List<PublicProfileResponse>> profiles(
+            @RequestParam(required = false) String ids) {
+        List<PublicProfileResponse> profiles = userRepository.findPublicProfiles(parse(ids))
+                .stream()
+                .map(row -> new PublicProfileResponse(row.id(), row.nickname(), row.avatarAssetId()))
+                .toList();
+        return ApiResponse.success(profiles);
+    }
+
+    /**
+     * Parsed by hand (not bound as List&lt;UUID&gt;) so every malformed shape
+     * answers a deterministic 400/40000 instead of falling through to the
+     * generic handler.
+     */
+    private static Set<UUID> parse(String ids) {
+        if (ids == null || ids.isBlank()) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR, "ids 必带且不得为空");
+        }
+        String[] parts = ids.split(",", -1);
+        if (parts.length > MAX_BATCH) {
+            throw new BusinessException(ErrorCode.VALIDATION_ERROR,
+                    "ids 一次最多 " + MAX_BATCH + " 个");
+        }
+        Set<UUID> parsed = new LinkedHashSet<>(parts.length);
+        for (String part : parts) {
+            try {
+                parsed.add(UUID.fromString(part.trim()));
+            } catch (IllegalArgumentException e) {
+                throw new BusinessException(ErrorCode.VALIDATION_ERROR, "ids 含非法 UUID");
+            }
+        }
+        return parsed;
+    }
+}

patbond-user/src/main/java/com/patbond/patbond/user/dto/PublicProfileResponse.java

@@ -0,0 +1,16 @@
+package com.patbond.patbond.user.dto;
+
+import java.util.UUID;
+
+/**
+ * One public profile in the /internal/users/profiles batch reply (D3-9 方案 B):
+ * exactly the fields another service may see — display name and the avatar
+ * asset pointer, nothing else (no phone, no username-vs-nickname distinction,
+ * no timestamps). The nickname→username fallback is applied HERE, on the
+ * owning side, so consumers never see or need the raw username. The avatar
+ * travels as an asset id, not a URL: URL signing is the consumer's read-side
+ * concern (community signs presigned GETs locally, T3-03 定型), and a signed
+ * URL would go stale inside the consumer's cache.
+ */
+public record PublicProfileResponse(UUID userId, String nickname, UUID avatarAssetId) {
+}

patbond-user/src/main/java/com/patbond/patbond/user/repository/UserRepository.java

@@ -4,6 +4,8 @@ import org.springframework.jdbc.core.simple.JdbcClient;
 import org.springframework.stereotype.Repository;
 
 import java.time.OffsetDateTime;
+import java.util.Collection;
+import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
 
@@ -36,6 +38,10 @@ public class UserRepository {
                           OffsetDateTime lockedUntil) {
     }
 
+    /** Public-profile projection; nickname already carries the username fallback. */
+    public record PublicProfileRow(UUID id, String nickname, UUID avatarAssetId) {
+    }
+
     /** Inserts the user row; created_at/updated_at come from the DB defaults. */
     public OffsetDateTime insertUser(UUID id, String username, String nickname, String phone) {
         return jdbcClient.sql("""
@@ -86,6 +92,31 @@ public class UserRepository {
                 .optional();
     }
 
+    /**
+     * Batch public-profile lookup for /internal/users/profiles (D3-9 方案 B).
+     * The nickname→username fallback happens in SQL (ck_users_nickname
+     * guarantees a stored nickname is trimmed and non-empty, so plain
+     * COALESCE suffices); soft-deleted users are simply absent — their
+     * tombstone shape is the caller's id-only fallback, indistinguishable
+     * from a user it failed to resolve.
+     */
+    public List<PublicProfileRow> findPublicProfiles(Collection<UUID> ids) {
+        if (ids.isEmpty()) {
+            return List.of();
+        }
+        return jdbcClient.sql("""
+                        SELECT id, COALESCE(nickname, username::text) AS nickname, avatar_asset_id
+                        FROM identity.users
+                        WHERE id IN (:ids) AND deleted_at IS NULL
+                        """)
+                .param("ids", List.copyOf(ids))
+                .query((rs, rowNum) -> new PublicProfileRow(
+                        rs.getObject("id", UUID.class),
+                        rs.getString("nickname"),
+                        rs.getObject("avatar_asset_id", UUID.class)))
+                .list();
+    }
+
     public Optional<AuthRow> findAuthByUsername(String username) {
         return jdbcClient.sql("""
                         SELECT u.id, u.username::text AS username, u.nickname, c.password_hash, c.locked_until

patbond-user/src/test/java/com/patbond/patbond/user/analytics/AnalyticsIntegrationTest.java

@@ -360,4 +360,115 @@ class AnalyticsIntegrationTest {
                 .andExpect(jsonPath("$.data.rejected").value(1))
                 .andExpect(jsonPath("$.data.results[0].reason").value("unknown_event_name"));
     }
+
+    @Test
+    void acceptsV3FeedViewedAggregateEvent() throws Exception {
+        String eventId = UUID.randomUUID().toString();
+        String body = """
+                {
+                  "events": [{
+                    "eventId": "%s",
+                    "eventName": "feed_viewed",
+                    "eventVersion": 1,
+                    "anonymousId": "019212aa-0000-7000-8000-000000000001",
+                    "sessionId": "019212aa-1111-7000-8000-000000000001",
+                    "clientTs": "%s",
+                    "appVersion": "1.2.0",
+                    "platform": "android",
+                    "osVersion": "android-14",
+                    "props": {
+                      "feedTab": "home",
+                      "durationMs": 45000,
+                      "impressionCount": 18,
+                      "loadMoreCount": 2,
+                      "refreshCount": 1
+                    }
+                  }]
+                }
+                """.formatted(eventId, OffsetDateTime.now());
+
+        mockMvc.perform(post("/api/v1/events")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(body))
+                .andExpect(status().isAccepted())
+                .andExpect(jsonPath("$.data.accepted").value(1))
+                .andExpect(jsonPath("$.data.results[0].status").value("accepted"));
+
+        String storedName = jdbcClient.sql(
+                        "SELECT event_name FROM platform.product_events WHERE event_id = :id")
+                .param("id", UUID.fromString(eventId))
+                .query(String.class)
+                .single();
+        assertThat(storedName).isEqualTo("feed_viewed");
+    }
+
+    @Test
+    void stripsContentIdPropsFromV3InteractionEvent() throws Exception {
+        String eventId = UUID.randomUUID().toString();
+        // 红线 2（report 06 §1.3）：行为客体的内容标识不进 props——白名单外的 postId 必须被剥离
+        String body = """
+                {
+                  "events": [{
+                    "eventId": "%s",
+                    "eventName": "post_liked",
+                    "eventVersion": 1,
+                    "anonymousId": "019212aa-0000-7000-8000-000000000001",
+                    "sessionId": "019212aa-1111-7000-8000-000000000001",
+                    "clientTs": "%s",
+                    "appVersion": "1.2.0",
+                    "platform": "ios",
+                    "osVersion": "ios-17",
+                    "props": {"source": "feed", "postId": "should_be_stripped"}
+                  }]
+                }
+                """.formatted(eventId, OffsetDateTime.now());
+
+        mockMvc.perform(post("/api/v1/events")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(body))
+                .andExpect(status().isAccepted())
+                .andExpect(jsonPath("$.data.accepted").value(1));
+
+        Map<String, Object> storedProps = jdbcClient.sql(
+                        "SELECT props::text FROM platform.product_events WHERE event_id = :id")
+                .param("id", UUID.fromString(eventId))
+                .query((rs, rowNum) -> {
+                    try {
+                        return new com.fasterxml.jackson.databind.ObjectMapper()
+                                .readValue(rs.getString(1), Map.class);
+                    } catch (Exception e) {
+                        throw new RuntimeException(e);
+                    }
+                })
+                .single();
+        assertThat(storedProps).containsEntry("source", "feed");
+        assertThat(storedProps).doesNotContainKey("postId");
+    }
+
+    @Test
+    void rejectedPerCardImpressionStaysOutOfDictionary() throws Exception {
+        // report 06 §1.2 裁定：逐卡曝光 post_impression 被否决，接收端按未知事件拒绝
+        String body = """
+                {
+                  "events": [{
+                    "eventId": "019212aa-5555-7000-8000-000000000001",
+                    "eventName": "post_impression",
+                    "eventVersion": 1,
+                    "anonymousId": "019212aa-0000-7000-8000-000000000001",
+                    "sessionId": "019212aa-1111-7000-8000-000000000001",
+                    "clientTs": "%s",
+                    "appVersion": "1.2.0",
+                    "platform": "android",
+                    "osVersion": "android-14"
+                  }]
+                }
+                """.formatted(OffsetDateTime.now());
+
+        mockMvc.perform(post("/api/v1/events")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(body))
+                .andExpect(status().isAccepted())
+                .andExpect(jsonPath("$.data.rejected").value(1))
+                .andExpect(jsonPath("$.data.results[0].reason").value("unknown_event_name"));
+    }
 }

patbond-user/src/test/java/com/patbond/patbond/user/analytics/EventDictionaryTest.java

@@ -5,8 +5,10 @@ import org.junit.jupiter.api.Test;
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Locks the dictionary v2 whitelist boundaries (report 06 §1.4/§1.5):
- * v1 auth funnel + page_viewed 正稿 + pet 域 3 事件 + health_record 域 7 事件.
+ * Locks the dictionary v3 whitelist boundaries (iteration-3 report 06
+ * §1.4/§1.5, ADR-020): v1 auth funnel + page_viewed 正稿 + v2 pet/
+ * health_record domains + M3 community increment (post 8, feed 2,
+ * interactions 8) + experiment_exposed (dictionary ahead of M4 use).
  * ADR-013's health_record_action stays removed — the per-action events
  * below replace it.
  */
@@ -77,4 +79,77 @@ class EventDictionaryTest {
         assertThat(EventDictionary.isKnownEvent("health_record_edit_started")).isFalse();
         assertThat(EventDictionary.isKnownEvent("health_record_delete_failed")).isFalse();
     }
+
+    @Test
+    void v3PostPublishFunnelMatchesDictionary() {
+        assertThat(EventDictionary.allowedProps("post_create_started"))
+                .containsExactlyInAnyOrder("entryPoint");
+        assertThat(EventDictionary.allowedProps("post_draft_saved"))
+                .containsExactlyInAnyOrder("trigger", "mediaCount");
+        assertThat(EventDictionary.allowedProps("post_publish_succeeded"))
+                .containsExactlyInAnyOrder(
+                        "durationMs", "mediaCount", "topicCount", "textLengthBucket", "fromDraft");
+        assertThat(EventDictionary.allowedProps("post_publish_failed"))
+                .containsExactlyInAnyOrder("failureReason", "errorCode", "httpStatus", "attemptSeq");
+        // post_deleted 单事件风格无专有属性（report 06 §1.4）
+        assertThat(EventDictionary.isKnownEvent("post_deleted")).isTrue();
+        assertThat(EventDictionary.allowedProps("post_deleted")).isEmpty();
+    }
+
+    @Test
+    void v3MediaUploadFunnelMatchesDictionary() {
+        assertThat(EventDictionary.allowedProps("post_media_upload_started"))
+                .containsExactlyInAnyOrder("mediaType", "sizeBucket");
+        assertThat(EventDictionary.allowedProps("post_media_upload_succeeded"))
+                .containsExactlyInAnyOrder("mediaType", "sizeBucket", "durationMs");
+        assertThat(EventDictionary.allowedProps("post_media_upload_failed"))
+                .containsExactlyInAnyOrder(
+                        "mediaType", "sizeBucket", "failureReason", "errorCode", "httpStatus", "attemptSeq");
+    }
+
+    @Test
+    void v3FeedDomainMatchesDictionary() {
+        // feed_viewed 是浏览段聚合曝光事件（report 06 §1.2）：只有计数与时长，绝无 postId 类内容标识
+        assertThat(EventDictionary.allowedProps("feed_viewed"))
+                .containsExactlyInAnyOrder(
+                        "feedTab", "durationMs", "impressionCount", "loadMoreCount", "refreshCount");
+        assertThat(EventDictionary.allowedProps("feed_load_failed"))
+                .containsExactlyInAnyOrder("feedTab", "loadType", "failureReason", "errorCode", "httpStatus");
+    }
+
+    @Test
+    void v3InteractionEventsMatchDictionary() {
+        // like/unlike、favorite/unfavorite、follow/unfollow 分立事件名（v2 废弃 action 属性同一逻辑）
+        assertThat(EventDictionary.allowedProps("post_liked")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("post_unliked")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("post_favorited")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("post_unfavorited")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("user_followed")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("user_unfollowed")).containsExactlyInAnyOrder("source");
+        assertThat(EventDictionary.allowedProps("comment_create_succeeded"))
+                .containsExactlyInAnyOrder("durationMs", "isReply", "textLengthBucket");
+        assertThat(EventDictionary.allowedProps("comment_create_failed"))
+                .containsExactlyInAnyOrder("failureReason", "errorCode", "httpStatus", "attemptSeq");
+    }
+
+    @Test
+    void v3ExperimentExposedRegisteredAheadOfM4Use() {
+        // A/B 前置 #5（report 06 §1.4）：M4 首实验才启用，字典与白名单本迭代一次进
+        assertThat(EventDictionary.allowedProps("experiment_exposed"))
+                .containsExactlyInAnyOrder("experimentKey", "variant");
+    }
+
+    @Test
+    void v3DeliberatelyAbsentEventsStayUnknown() {
+        // report 06 §1.2：逐卡曝光被否决，不设 post_impression；§1.4 取舍：
+        // 帖子浏览由 page_viewed(post_detail) 覆盖、评论不设 started、单点互动不埋失败；
+        // §1.6 缺口 3：话题关注 UI 定稿前挂起
+        assertThat(EventDictionary.isKnownEvent("post_impression")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("post_viewed")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("comment_create_started")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("post_like_failed")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("user_follow_failed")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("topic_followed")).isFalse();
+        assertThat(EventDictionary.isKnownEvent("topic_unfollowed")).isFalse();
+    }
 }

patbond-user/src/test/java/com/patbond/patbond/user/contract/ContractValidator.java

@@ -0,0 +1,256 @@
+package com.patbond.patbond.user.contract;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.math.BigDecimal;
+import java.time.LocalDate;
+import java.time.OffsetDateTime;
+import java.time.format.DateTimeParseException;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import static com.patbond.patbond.user.contract.OpenApiContract.cast;
+import static com.patbond.patbond.user.contract.OpenApiContract.list;
+import static com.patbond.patbond.user.contract.OpenApiContract.map;
+
+/**
+ * Validates an actual HTTP response against the frozen contract, strictly:
+ *
+ * <ul>
+ *   <li>the operation and the status must be declared;</li>
+ *   <li>required fields must be present; a null value needs {@code nullable};</li>
+ *   <li>fields the schema does not declare are rejected (this is what catches
+ *       a renamed or newly leaked field — plain OpenAPI semantics would allow
+ *       extra properties, but the frozen contract is "exactly these fields");</li>
+ *   <li>types, enum membership, uuid / date-time / date formats and
+ *       min/max(Length) bounds are checked.</li>
+ * </ul>
+ *
+ * Behavioural semantics (state machines, anti-enumeration, permission logic)
+ * stay with the existing integration tests — this class only pins structure.
+ */
+final class ContractValidator {
+
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    private final OpenApiContract contract;
+
+    ContractValidator(OpenApiContract contract) {
+        this.contract = contract;
+    }
+
+    /**
+     * @return drift findings, empty when the response conforms; each entry is
+     *         a human-readable "where: what" line
+     */
+    List<String> validateResponse(String method, String pathTemplate, int status, String body) {
+        List<String> errors = new ArrayList<>();
+        String opKey = method + " " + pathTemplate;
+        Map<String, Object> op = contract.operation(opKey);
+        if (op == null) {
+            errors.add("契约未声明该操作: " + opKey);
+            return errors;
+        }
+        Object respNode = map(op, "responses").get(String.valueOf(status));
+        if (respNode == null) {
+            errors.add("契约未为 " + opKey + " 声明状态码 " + status);
+            return errors;
+        }
+        Map<String, Object> content = map(contract.resolve(cast(respNode)), "content");
+        if (content == null) {
+            return errors; // response declared without a body
+        }
+        Map<String, Object> schema = map(map(content, "application/json"), "schema");
+        if (schema == null) {
+            errors.add(opKey + " " + status + ": 契约声明了 content 但无 application/json schema");
+            return errors;
+        }
+        JsonNode node;
+        try {
+            node = MAPPER.readTree(body);
+        } catch (JsonProcessingException e) {
+            errors.add(opKey + " " + status + ": 响应体不是合法 JSON: " + e.getOriginalMessage());
+            return errors;
+        }
+        validate(schema, node, "$", errors);
+        return errors;
+    }
+
+    private void validate(Map<String, Object> rawSchema, JsonNode node, String loc, List<String> errors) {
+        Map<String, Object> schema = effectiveSchema(rawSchema);
+        if (node == null || node.isMissingNode()) {
+            errors.add(loc + ": 字段缺失");
+            return;
+        }
+        if (node.isNull()) {
+            if (!Boolean.TRUE.equals(schema.get("nullable"))) {
+                errors.add(loc + ": 为 null，但契约未声明 nullable");
+            }
+            return;
+        }
+        List<Object> allowed = list(schema, "enum");
+        if (allowed != null && !enumMatches(allowed, node)) {
+            errors.add(loc + ": 值 " + node + " 不在契约枚举 " + allowed + " 内");
+        }
+        String type = (String) schema.get("type");
+        if (type == null) {
+            type = schema.containsKey("properties") ? "object" : null;
+        }
+        if (type == null) {
+            return;
+        }
+        switch (type) {
+            case "object" -> validateObject(schema, node, loc, errors);
+            case "array" -> validateArray(schema, node, loc, errors);
+            case "string" -> validateString(schema, node, loc, errors);
+            case "integer" -> {
+                if (!node.isIntegralNumber()) {
+                    errors.add(loc + ": 应为 integer，实际 " + node.getNodeType() + " " + node);
+                } else {
+                    checkRange(schema, node.decimalValue(), loc, errors);
+                }
+            }
+            case "number" -> {
+                if (!node.isNumber()) {
+                    errors.add(loc + ": 应为 number，实际 " + node.getNodeType() + " " + node);
+                } else {
+                    checkRange(schema, node.decimalValue(), loc, errors);
+                }
+            }
+            case "boolean" -> {
+                if (!node.isBoolean()) {
+                    errors.add(loc + ": 应为 boolean，实际 " + node.getNodeType() + " " + node);
+                }
+            }
+            default -> errors.add(loc + ": 契约测试不支持的 type " + type);
+        }
+    }
+
+    /**
+     * Resolves $refs and flattens the v1.3.0 {@code nullable + allOf: [$ref]}
+     * pattern into one plain schema (branch keys first, sibling keys — e.g.
+     * the outer {@code nullable} — win). The frozen contract only ever uses
+     * single-branch allOf, so a shallow merge is exact; overlapping
+     * {@code properties} across branches would need a deep merge and are not
+     * supported.
+     */
+    private Map<String, Object> effectiveSchema(Map<String, Object> rawSchema) {
+        Map<String, Object> schema = contract.resolve(rawSchema);
+        List<Object> allOf = list(schema, "allOf");
+        if (allOf == null) {
+            return schema;
+        }
+        Map<String, Object> merged = new LinkedHashMap<>();
+        for (Object branch : allOf) {
+            merged.putAll(effectiveSchema(cast(branch)));
+        }
+        schema.forEach((key, value) -> {
+            if (!"allOf".equals(key)) {
+                merged.put(key, value);
+            }
+        });
+        return merged;
+    }
+
+    private void validateObject(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isObject()) {
+            errors.add(loc + ": 应为 object，实际 " + node.getNodeType());
+            return;
+        }
+        Map<String, Object> props = map(schema, "properties");
+        List<Object> required = list(schema, "required");
+        if (required != null) {
+            for (Object r : required) {
+                if (!node.has((String) r)) {
+                    errors.add(loc + "." + r + ": 契约必填字段缺失");
+                }
+            }
+        }
+        Object additional = schema.get("additionalProperties");
+        boolean open = Boolean.TRUE.equals(additional) || additional instanceof Map;
+        Iterator<Map.Entry<String, JsonNode>> fields = node.fields();
+        while (fields.hasNext()) {
+            Map.Entry<String, JsonNode> field = fields.next();
+            Map<String, Object> propSchema = props == null ? null : cast(props.get(field.getKey()));
+            if (propSchema != null) {
+                validate(propSchema, field.getValue(), loc + "." + field.getKey(), errors);
+            } else if (!open) {
+                errors.add(loc + "." + field.getKey() + ": 契约未声明的字段（结构漂移）");
+            }
+        }
+    }
+
+    private void validateArray(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isArray()) {
+            errors.add(loc + ": 应为 array，实际 " + node.getNodeType());
+            return;
+        }
+        Map<String, Object> items = map(schema, "items");
+        if (items == null) {
+            return;
+        }
+        int i = 0;
+        for (JsonNode element : node) {
+            validate(items, element, loc + "[" + i++ + "]", errors);
+        }
+    }
+
+    private void validateString(Map<String, Object> schema, JsonNode node, String loc, List<String> errors) {
+        if (!node.isTextual()) {
+            errors.add(loc + ": 应为 string，实际 " + node.getNodeType() + " " + node);
+            return;
+        }
+        String value = node.asText();
+        String format = (String) schema.get("format");
+        if (format != null) {
+            try {
+                switch (format) {
+                    case "uuid" -> {
+                        if (value.length() != 36) {
+                            throw new IllegalArgumentException("非规范 UUID 长度");
+                        }
+                        java.util.UUID.fromString(value);
+                    }
+                    case "date-time" -> OffsetDateTime.parse(value);
+                    case "date" -> LocalDate.parse(value);
+                    default -> { /* password 等纯标注格式不校验 */ }
+                }
+            } catch (IllegalArgumentException | DateTimeParseException e) {
+                errors.add(loc + ": \"" + value + "\" 不符合 format=" + format);
+            }
+        }
+        if (schema.get("minLength") instanceof Number min && value.length() < min.intValue()) {
+            errors.add(loc + ": 长度 " + value.length() + " 小于契约 minLength " + min);
+        }
+        if (schema.get("maxLength") instanceof Number max && value.length() > max.intValue()) {
+            errors.add(loc + ": 长度 " + value.length() + " 大于契约 maxLength " + max);
+        }
+    }
+
+    private static void checkRange(Map<String, Object> schema, BigDecimal value, String loc, List<String> errors) {
+        if (schema.get("minimum") instanceof Number min
+                && value.compareTo(new BigDecimal(min.toString())) < 0) {
+            errors.add(loc + ": 值 " + value + " 小于契约 minimum " + min);
+        }
+        if (schema.get("maximum") instanceof Number max
+                && value.compareTo(new BigDecimal(max.toString())) > 0) {
+            errors.add(loc + ": 值 " + value + " 大于契约 maximum " + max);
+        }
+    }
+
+    private static boolean enumMatches(List<Object> allowed, JsonNode node) {
+        if (node.isTextual()) {
+            return allowed.contains(node.asText());
+        }
+        if (node.isIntegralNumber()) {
+            long v = node.longValue();
+            return allowed.stream().anyMatch(a -> a instanceof Number n && n.longValue() == v);
+        }
+        return false;
+    }
+}

patbond-user/src/test/java/com/patbond/patbond/user/contract/MediaContractConformanceTest.java

@@ -0,0 +1,274 @@
+package com.patbond.patbond.user.contract;
+
+import com.jayway.jsonpath.JsonPath;
+import com.patbond.patbond.user.TestcontainersConfiguration;
+import com.patbond.patbond.user.support.TestJwtKeys;
+import org.junit.jupiter.api.MethodOrderer;
+import org.junit.jupiter.api.Order;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestMethodOrder;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.MediaType;
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.test.context.DynamicPropertyRegistry;
+import org.springframework.test.context.DynamicPropertySource;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.MvcResult;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
+import org.testcontainers.containers.MinIOContainer;
+import org.testcontainers.utility.DockerImageName;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+
+/**
+ * T3-20（M3 第二波收尾）：media 域 2 个操作（两步上传，属 user 模块）补进契约
+ * 一致性保障，机制与 patbond-pet 的 ContractConformanceTest 同构——对冻结契约
+ * v1.3.0（快照 {@code src/test/resources/contract/openapi-v1.3.0.yaml}，正典在
+ * doc 仓 {@code docs/api/openapi.yaml}）逐操作真实起服务发请求（真实 MinIO
+ * Testcontainer，直传走真实 HTTP PUT），用 {@link ContractValidator} 严格校验
+ * 响应结构，最后以全响应矩阵门禁兜底（8 个单元格，无豁免）。
+ *
+ * <p>auth 域 6 操作在 patbond-auth、pets 域 18 操作在 patbond-pet、community 域
+ * 17 操作在 patbond-community 的同构测试内（快照同一份）。
+ */
+@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
+@SpringBootTest
+@AutoConfigureMockMvc
+@Import(TestcontainersConfiguration.class)
+class MediaContractConformanceTest {
+
+    private static final OpenApiContract CONTRACT = OpenApiContract.load();
+    private static final ContractValidator VALIDATOR = new ContractValidator(CONTRACT);
+
+    /** 已被真实响应校验过的 (操作, 状态码) 单元格。 */
+    private static final Set<String> COVERED = ConcurrentHashMap.newKeySet();
+
+    /** media 域 2 个操作（= 契约中 tags ∈ {media}）。 */
+    private static final List<String> MEDIA_OPERATIONS = List.of(
+            "POST /api/v1/media/uploads",
+            "POST /api/v1/media/uploads/{assetId}/complete");
+
+    /** 与 docker-compose.yml 的 minio 服务钉同一 tag（ADR-016 三环境零分叉）。 */
+    private static final MinIOContainer MINIO = new MinIOContainer(
+            DockerImageName.parse("minio/minio:RELEASE.2025-04-22T22-12-26Z"))
+            // 值仅为测试占位（dummy），非真实凭证
+            .withUserName("minio-dummy-access")
+            .withPassword("minio-dummy-secret");
+
+    private static final HttpClient HTTP = HttpClient.newBuilder()
+            .connectTimeout(Duration.ofSeconds(10))
+            .build();
+
+    private static final byte[] FAKE_JPEG = fakeJpeg();
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private JdbcClient jdbcClient;
+
+    @DynamicPropertySource
+    static void wireMedia(DynamicPropertyRegistry registry) {
+        MINIO.start();
+        registry.add("patbond.jwt.public-key", TestJwtKeys::publicPem);
+        registry.add("patbond.media.endpoint", MINIO::getS3URL);
+        registry.add("patbond.media.access-key", MINIO::getUserName);
+        registry.add("patbond.media.secret-key", MINIO::getPassword);
+    }
+
+    // ---- 校验骨架 ------------------------------------------------------
+
+    private String verified(MockHttpServletRequestBuilder rq, String method,
+                            String pathTemplate, int expectedStatus) throws Exception {
+        MvcResult result = mockMvc.perform(rq).andReturn();
+        int actual = result.getResponse().getStatus();
+        String body = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
+        assertThat(actual)
+                .as("%s %s 的 HTTP 状态（响应体: %s）", method, pathTemplate, body)
+                .isEqualTo(expectedStatus);
+        List<String> drift = VALIDATOR.validateResponse(method, pathTemplate, actual, body);
+        assertThat(drift).as("%s %s %d 响应与冻结契约漂移", method, pathTemplate, actual).isEmpty();
+        COVERED.add(method + " " + pathTemplate + " " + actual);
+        return body;
+    }
+
+    private String verifiedError(MockHttpServletRequestBuilder rq, String method,
+                                 String pathTemplate, int status, int bizCode) throws Exception {
+        String body = verified(rq, method, pathTemplate, status);
+        assertThat((Integer) JsonPath.read(body, "$.code"))
+                .as("%s %s %d 的业务错误码", method, pathTemplate, status)
+                .isEqualTo(bizCode);
+        return body;
+    }
+
+    private static byte[] fakeJpeg() {
+        byte[] bytes = new byte[2048];
+        for (int i = 0; i < bytes.length; i++) {
+            bytes[i] = (byte) (i * 31);
+        }
+        bytes[0] = (byte) 0xFF;
+        bytes[1] = (byte) 0xD8; // JPEG SOI，凑个像样的文件头
+        return bytes;
+    }
+
+    private UUID newUser(String username) {
+        UUID id = UUID.randomUUID();
+        jdbcClient.sql("INSERT INTO identity.users (id, username) VALUES (:id, :username)")
+                .param("id", id)
+                .param("username", username)
+                .update();
+        return id;
+    }
+
+    private static String bearer(UUID userId) {
+        return "Bearer " + TestJwtKeys.accessToken(
+                TestJwtKeys.KEY_PAIR.getPrivate(), userId, Duration.ofMinutes(15));
+    }
+
+    /** 创建上传（经 verified，201 凭据形态即被契约校验），返回响应体。 */
+    private String createUpload(UUID user, long byteSize) throws Exception {
+        return verified(post("/api/v1/media/uploads")
+                        .header("Authorization", bearer(user))
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {"kind":"image","purpose":"post_image",
+                                 "mimeType":"image/jpeg","byteSize":%d}
+                                """.formatted(byteSize)),
+                "POST", "/api/v1/media/uploads", 201);
+    }
+
+    /** 按凭据把字节真实 PUT 到 MinIO。 */
+    private void directPut(String createdBody, byte[] bytes) throws Exception {
+        String uploadUrl = JsonPath.read(createdBody, "$.data.uploadUrl");
+        Map<String, String> headers = JsonPath.read(createdBody, "$.data.requiredHeaders");
+        HttpRequest.Builder put = HttpRequest.newBuilder(URI.create(uploadUrl))
+                .PUT(HttpRequest.BodyPublishers.ofByteArray(bytes));
+        headers.forEach(put::header);
+        int status = HTTP.send(put.build(), HttpResponse.BodyHandlers.discarding()).statusCode();
+        assertThat(status).as("预签名直传应被 MinIO 接受").isEqualTo(200);
+    }
+
+    private MockHttpServletRequestBuilder completeRequest(UUID user, String assetId) {
+        return post("/api/v1/media/uploads/{assetId}/complete", assetId)
+                .header("Authorization", bearer(user));
+    }
+
+    // ---- 成功路径 ------------------------------------------------------
+
+    @Test
+    @Order(1)
+    void twoStepUploadSuccessShapes() throws Exception {
+        UUID user = newUser("contract_media_owner");
+        String created = createUpload(user, FAKE_JPEG.length);
+        String assetId = JsonPath.read(created, "$.data.assetId");
+        directPut(created, FAKE_JPEG);
+
+        String completed = verified(completeRequest(user, assetId),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 200);
+        assertThat((String) JsonPath.read(completed, "$.data.status")).isEqualTo("ready");
+        assertThat((String) JsonPath.read(completed, "$.data.url"))
+                .as("ready 资产必须带预签名 GET URL").isNotNull();
+
+        // 幂等重复确认：同格 200，同一 asset
+        String again = verified(completeRequest(user, assetId),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 200);
+        assertThat((String) JsonPath.read(again, "$.data.id")).isEqualTo(assetId);
+    }
+
+    // ---- 错误信封 ------------------------------------------------------
+
+    @Test
+    @Order(2)
+    void errorEnvelopesMatchContract() throws Exception {
+        UUID user = newUser("contract_media_err");
+
+        // 400/40000：mime 白名单外；complete 的畸形 assetId
+        verifiedError(post("/api/v1/media/uploads")
+                        .header("Authorization", bearer(user))
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {"kind":"image","purpose":"post_image",
+                                 "mimeType":"image/gif","byteSize":1024}
+                                """),
+                "POST", "/api/v1/media/uploads", 400, 40000);
+        verifiedError(completeRequest(user, "not-a-uuid"),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 400, 40000);
+
+        // 401/40101：两操作均缺 token
+        verifiedError(post("/api/v1/media/uploads")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("""
+                                {"kind":"image","purpose":"post_image",
+                                 "mimeType":"image/jpeg","byteSize":1024}
+                                """),
+                "POST", "/api/v1/media/uploads", 401, 40101);
+        verifiedError(post("/api/v1/media/uploads/{assetId}/complete", UUID.randomUUID()),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 401, 40101);
+
+        // 404/40405：他人 asset 与不存在 asset 防枚举合并
+        UUID intruder = newUser("contract_media_intruder");
+        String created = createUpload(user, FAKE_JPEG.length);
+        String assetId = JsonPath.read(created, "$.data.assetId");
+        verifiedError(completeRequest(intruder, assetId),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 404, 40405);
+        verifiedError(completeRequest(user, UUID.randomUUID().toString()),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 404, 40405);
+
+        // 422/42205：直传完成前确认（asset 保持 uploading 可重试）
+        verifiedError(completeRequest(user, assetId),
+                "POST", "/api/v1/media/uploads/{assetId}/complete", 422, 42205);
+    }
+
+    // ---- 快照与覆盖门禁 -------------------------------------------------
+
+    /**
+     * 冻结快照守卫：与 pet/auth/community 侧同一纪律——正典契约升版时必须同步
+     * 复制新快照并更新期望值，忘记同步在 CI 立即变红。
+     */
+    @Test
+    @Order(98)
+    void frozenSnapshotIsTheExpectedContractVersion() {
+        assertThat(CONTRACT.version()).isEqualTo("1.3.0");
+        assertThat(CONTRACT.paths()).hasSize(31);
+        assertThat(CONTRACT.operations()).hasSize(43);
+        assertThat(CONTRACT.schemas()).hasSize(72);
+        assertThat(CONTRACT.operationsTagged(Set.of("media")))
+                .containsExactlyInAnyOrderElementsOf(MEDIA_OPERATIONS);
+    }
+
+    /**
+     * 全矩阵覆盖门禁：media 域 2 个操作声明的每个 (操作, 状态码) 都必须被
+     * 前面的测试真实触发并通过契约校验（8 个单元格，无豁免）。
+     */
+    @Test
+    @Order(99)
+    void everyDeclaredResponseCellIsExercised() {
+        List<String> missing = new ArrayList<>();
+        for (String op : MEDIA_OPERATIONS) {
+            for (int status : CONTRACT.responseStatuses(op)) {
+                String cell = op + " " + status;
+                if (!COVERED.contains(cell)) {
+                    missing.add(cell);
+                }
+            }
+        }
+        assertThat(missing).as("契约声明但未被契约测试触发的响应单元格").isEmpty();
+    }
+}

patbond-user/src/test/java/com/patbond/patbond/user/contract/OpenApiContract.java

@@ -0,0 +1,151 @@
+package com.patbond.patbond.user.contract;
+
+import org.yaml.snakeyaml.Yaml;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * The frozen v1.3.0 OpenAPI contract, loaded from the test-resource snapshot
+ * {@code /contract/openapi-v1.3.0.yaml}.
+ *
+ * <p><b>Sync discipline (T2-09, extended by T3-19)</b>: the canonical
+ * contract lives in the doc repo at {@code docs/api/openapi.yaml}; this
+ * snapshot is a byte-identical copy taken at freeze time, and this class is
+ * the module-local copy of the pet module's contract framework (same
+ * per-module duplication discipline as BearerAuthFilter). Whenever the
+ * canonical contract changes, copy it into every framework-carrying module
+ * (patbond-pet / patbond-auth / patbond-community / patbond-user) under the
+ * new version's file name and update each conformance test (expected version
+ * + snapshot counts). The guard test on {@code info.version} makes a forgotten
+ * sync fail loudly in CI instead of silently testing against a stale
+ * contract.
+ *
+ * <p>Only the subset of OpenAPI 3.0 this contract actually uses is supported:
+ * local {@code #/} refs, plain types, {@code nullable}, {@code enum},
+ * {@code required}, {@code properties}, {@code items}, and the v1.3.0
+ * single-branch {@code nullable + allOf: [$ref]} pattern (merged in
+ * {@link ContractValidator}) — no oneOf/anyOf.
+ */
+final class OpenApiContract {
+
+    static final String RESOURCE = "/contract/openapi-v1.3.0.yaml";
+
+    private static final Set<String> HTTP_METHODS =
+            Set.of("get", "put", "post", "delete", "options", "head", "patch", "trace");
+
+    private final Map<String, Object> root;
+
+    private OpenApiContract(Map<String, Object> root) {
+        this.root = root;
+    }
+
+    static OpenApiContract load() {
+        try (InputStream in = Objects.requireNonNull(
+                OpenApiContract.class.getResourceAsStream(RESOURCE),
+                "契约快照缺失: " + RESOURCE)) {
+            return new OpenApiContract(new Yaml().load(in));
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+    String version() {
+        return (String) map(root, "info").get("version");
+    }
+
+    Map<String, Object> paths() {
+        return map(root, "paths");
+    }
+
+    Map<String, Object> schemas() {
+        return map(map(root, "components"), "schemas");
+    }
+
+    /** All declared operations as "METHOD pathTemplate" (insertion order). */
+    Set<String> operations() {
+        Set<String> ops = new LinkedHashSet<>();
+        paths().forEach((path, item) -> cast(item).forEach((method, op) -> {
+            if (HTTP_METHODS.contains(method)) {
+                ops.add(method.toUpperCase(Locale.ROOT) + " " + path);
+            }
+        }));
+        return ops;
+    }
+
+    /** Operations whose first tag is in {@code tags}, as "METHOD pathTemplate". */
+    Set<String> operationsTagged(Set<String> tags) {
+        Set<String> ops = new LinkedHashSet<>();
+        for (String key : operations()) {
+            List<Object> opTags = list(operation(key), "tags");
+            if (opTags != null && opTags.stream().anyMatch(tags::contains)) {
+                ops.add(key);
+            }
+        }
+        return ops;
+    }
+
+    /** Declared response statuses of an operation, as ints. */
+    Set<Integer> responseStatuses(String operationKey) {
+        Set<Integer> statuses = new LinkedHashSet<>();
+        map(operation(operationKey), "responses")
+                .keySet().forEach(s -> statuses.add(Integer.parseInt(s)));
+        return statuses;
+    }
+
+    /** The single 2xx status the operation declares. */
+    int successStatus(String operationKey) {
+        return responseStatuses(operationKey).stream()
+                .filter(s -> s >= 200 && s < 300)
+                .reduce((a, b) -> {
+                    throw new IllegalStateException("多个 2xx 响应: " + operationKey);
+                })
+                .orElseThrow(() -> new IllegalStateException("无 2xx 响应: " + operationKey));
+    }
+
+    /** Operation object for "METHOD pathTemplate", or null when undeclared. */
+    Map<String, Object> operation(String operationKey) {
+        String[] parts = operationKey.split(" ", 2);
+        Map<String, Object> pathItem = map(paths(), parts[1]);
+        return pathItem == null ? null : map(pathItem, parts[0].toLowerCase(Locale.ROOT));
+    }
+
+    /** Follows local $ref chains; non-ref maps come back unchanged. */
+    Map<String, Object> resolve(Map<String, Object> node) {
+        while (node != null && node.get("$ref") instanceof String ref) {
+            if (!ref.startsWith("#/")) {
+                throw new IllegalStateException("仅支持本地 $ref: " + ref);
+            }
+            Map<String, Object> cur = root;
+            for (String seg : ref.substring(2).split("/")) {
+                cur = map(cur, seg);
+                if (cur == null) {
+                    throw new IllegalStateException("$ref 指向不存在的节点: " + ref);
+                }
+            }
+            node = cur;
+        }
+        return node;
+    }
+
+    @SuppressWarnings("unchecked")
+    static Map<String, Object> cast(Object o) {
+        return (Map<String, Object>) o;
+    }
+
+    static Map<String, Object> map(Map<String, Object> m, String key) {
+        return m == null ? null : cast(m.get(key));
+    }
+
+    @SuppressWarnings("unchecked")
+    static List<Object> list(Map<String, Object> m, String key) {
+        return m == null ? null : (List<Object>) m.get(key);
+    }
+}

patbond-user/src/test/java/com/patbond/patbond/user/controller/InternalProfileEndpointTest.java

@@ -0,0 +1,190 @@
+package com.patbond.patbond.user.controller;
+
+import com.jayway.jsonpath.JsonPath;
+import com.patbond.patbond.user.TestcontainersConfiguration;
+import com.patbond.patbond.user.security.InternalAuthFilter;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.annotation.Import;
+import org.springframework.http.MediaType;
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.request.MockHttpServletRequestBuilder;
+
+import java.time.OffsetDateTime;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * /internal/users/profiles (D3-9 方案 B, T3-05): service auth, batch limits,
+ * the nickname→username fallback, avatar pointer passthrough, and the
+ * silent-absence semantics for unknown or soft-deleted users.
+ */
+@SpringBootTest
+@AutoConfigureMockMvc
+@Import(TestcontainersConfiguration.class)
+class InternalProfileEndpointTest {
+
+    private static final String INTERNAL_TOKEN = "test-internal-token";
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private JdbcClient jdbcClient;
+
+    private MockHttpServletRequestBuilder profiles(String ids) {
+        return get("/internal/users/profiles")
+                .header(InternalAuthFilter.HEADER, INTERNAL_TOKEN)
+                .queryParam("ids", ids);
+    }
+
+    private String registerUser(String username) throws Exception {
+        String body = mockMvc.perform(post("/internal/users")
+                        .header(InternalAuthFilter.HEADER, INTERNAL_TOKEN)
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content("{\"username\":\"%s\",\"password\":\"secret123\"}".formatted(username)))
+                .andExpect(status().isOk())
+                .andReturn().getResponse().getContentAsString();
+        return JsonPath.read(body, "$.data.id");
+    }
+
+    private String freshUsername() {
+        return "prof" + Long.toHexString(ThreadLocalRandom.current().nextLong() & 0x7FFFFFFFFFFFFFFFL);
+    }
+
+    /** Profiles of a successful reply, keyed by userId. */
+    private Map<String, Map<String, Object>> fetch(String ids) throws Exception {
+        String body = mockMvc.perform(profiles(ids))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.code").value(0))
+                .andReturn().getResponse().getContentAsString();
+        List<Map<String, Object>> rows = JsonPath.read(body, "$.data");
+        return rows.stream().collect(Collectors.toMap(
+                row -> (String) row.get("userId"), Function.identity()));
+    }
+
+    private UUID insertReadyAvatarAsset(UUID ownerId) {
+        UUID assetId = UUID.randomUUID();
+        jdbcClient.sql("""
+                        INSERT INTO media.assets
+                            (id, owner_user_id, kind, purpose, storage_type, bucket, object_key,
+                             mime_type, byte_size, status, ready_at)
+                        VALUES (:id, :owner, 'image', 'user_avatar', 'object', 'patbond-media',
+                                :objectKey, 'image/jpeg', 123, 'ready', :readyAt)
+                        """)
+                .param("id", assetId)
+                .param("owner", ownerId)
+                .param("objectKey", "user_avatar/2026/09/" + assetId + ".jpg")
+                .param("readyAt", OffsetDateTime.now())
+                .update();
+        jdbcClient.sql("UPDATE identity.users SET avatar_asset_id = :assetId WHERE id = :id")
+                .param("assetId", assetId)
+                .param("id", ownerId)
+                .update();
+        return assetId;
+    }
+
+    @Test
+    void rejectsCallsWithoutTheServiceSecret() throws Exception {
+        mockMvc.perform(get("/internal/users/profiles").queryParam("ids", UUID.randomUUID().toString()))
+                .andExpect(status().isUnauthorized())
+                .andExpect(jsonPath("$.code").value(40101));
+        mockMvc.perform(get("/internal/users/profiles")
+                        .header(InternalAuthFilter.HEADER, "wrong-token")
+                        .queryParam("ids", UUID.randomUUID().toString()))
+                .andExpect(status().isUnauthorized())
+                .andExpect(jsonPath("$.code").value(40101));
+    }
+
+    @Test
+    void returnsNicknameWhenSetAndFallsBackToUsernameWhenNot() throws Exception {
+        String withNickname = registerUser(freshUsername());
+        String withoutNickname = freshUsername();
+        String withoutNicknameId = registerUser(withoutNickname);
+        jdbcClient.sql("UPDATE identity.users SET nickname = '毛毛的铲屎官' WHERE id = :id")
+                .param("id", UUID.fromString(withNickname))
+                .update();
+
+        Map<String, Map<String, Object>> profiles = fetch(withNickname + "," + withoutNicknameId);
+        assertThat(profiles).hasSize(2);
+        assertThat(profiles.get(withNickname).get("nickname")).isEqualTo("毛毛的铲屎官");
+        assertThat(profiles.get(withoutNicknameId).get("nickname")).isEqualTo(withoutNickname);
+    }
+
+    @Test
+    void passesTheAvatarAssetPointerThroughAndNullWithoutAvatar() throws Exception {
+        String withAvatar = registerUser(freshUsername());
+        String withoutAvatar = registerUser(freshUsername());
+        UUID assetId = insertReadyAvatarAsset(UUID.fromString(withAvatar));
+
+        Map<String, Map<String, Object>> profiles = fetch(withAvatar + "," + withoutAvatar);
+        assertThat(profiles.get(withAvatar).get("avatarAssetId")).isEqualTo(assetId.toString());
+        assertThat(profiles.get(withoutAvatar).get("avatarAssetId")).isNull();
+    }
+
+    @Test
+    void unknownAndSoftDeletedIdsAreSilentlyAbsent() throws Exception {
+        String live = registerUser(freshUsername());
+        String deleted = registerUser(freshUsername());
+        jdbcClient.sql("UPDATE identity.users SET deleted_at = now(), status = 'deleted' WHERE id = :id")
+                .param("id", UUID.fromString(deleted))
+                .update();
+
+        Map<String, Map<String, Object>> profiles =
+                fetch(live + "," + deleted + "," + UUID.randomUUID());
+        assertThat(profiles).containsOnlyKeys(live);
+    }
+
+    @Test
+    void missingOrBlankIdsIsA400() throws Exception {
+        mockMvc.perform(get("/internal/users/profiles")
+                        .header(InternalAuthFilter.HEADER, INTERNAL_TOKEN))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+        mockMvc.perform(profiles("  "))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void malformedUuidIsA400() throws Exception {
+        mockMvc.perform(profiles(UUID.randomUUID() + ",not-a-uuid"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void moreThanFiftyIdsIsA400AndExactlyFiftyIsNot() throws Exception {
+        String fifty = IntStream.range(0, 50)
+                .mapToObj(i -> UUID.randomUUID().toString())
+                .collect(Collectors.joining(","));
+        mockMvc.perform(profiles(fifty))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.length()").value(0));
+        mockMvc.perform(profiles(fifty + "," + UUID.randomUUID()))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.code").value(40000));
+    }
+
+    @Test
+    void duplicateIdsCollapseToOneRow() throws Exception {
+        String user = registerUser(freshUsername());
+        mockMvc.perform(profiles(user + "," + user))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.data.length()").value(1));
+    }
+}