docs: M3 第一波收口——报告 09~14 与契约草案入档挂导航

- 09 V5+community 骨架（191→206）、10 埋点队列三项（272→286）、
  11 契约草案（13 路径/19 操作）、12 防泄漏三仓落地、
  13 media MinIO 闭环 + auth 契约测试（→226，抓修 1 漂移）、14 收口总表
- backend-modules.md 更新五模块/六容器口径
- 媒体凭据形态已定型（契约冻结输入），剩余待定型点在 T3-04/05

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

mkdocs.yml

@@ -72,6 +72,12 @@ nav:
           - 06 埋点规划: development/iterations/iteration-3/06-experiment-tracking-plan.md
           - 07 证据基线审计: development/iterations/iteration-3/07-evidence-baseline-audit.md
           - 08 Git 工作流规划: development/iterations/iteration-3/08-git-workflow-plan.md
+          - 09 社区地基报告: development/iterations/iteration-3/09-community-foundation-report.md
+          - 10 埋点队列加固: development/iterations/iteration-3/10-analytics-queue-hardening.md
+          - 11 社区契约起草: development/iterations/iteration-3/11-community-contract-draft.md
+          - 12 防泄漏检查落地: development/iterations/iteration-3/12-secret-scan-rollout.md
+          - 13 media MinIO 闭环: development/iterations/iteration-3/13-media-minio-report.md
+          - 14 第一波收口: development/iterations/iteration-3/14-wave1-closure.md
   - API:
       - 契约说明: api/index.md
   - 架构: