docs: M2 开工前分析 10 份报告入档 + ADR-009~015 拍板决策

- iteration-2 报告 01-08（PM 拆解/后端/Flutter 评估/现实核查/UI 规范/埋点规划/证据基线/Git 规划），04、06 已由正式角色复核定稿
- mkdocs 挂「第二迭代」导航，build --strict 通过
- ADR-009 新建 patbond-pet 模块、ADR-010 照片剪出 M2、ADR-011 dev 主干/master 发布、ADR-012 北极星与 H1-H4、ADR-013 废弃 health_record_action、ADR-014 DEBT-1 随 M2、ADR-015 照护人邀请后置

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

mkdocs.yml

@@ -30,6 +30,15 @@ nav:
           - 18 真机联调 E2E 报告: development/iterations/iteration-1/18-e2e-integration-report.md
           - 19 埋点系统实现报告: development/iterations/iteration-1/19-analytics-implementation-report.md
           - 20 第一迭代收官总结: development/iterations/iteration-1/20-iteration-1-summary.md
+      - 第二迭代:
+          - 01 任务分解: development/iterations/iteration-2/01-pm-task-breakdown.md
+          - 02 后端技术评估: development/iterations/iteration-2/02-backend-technical-assessment.md
+          - 03 Flutter 技术评估: development/iterations/iteration-2/03-flutter-technical-assessment.md
+          - 04 现状核实: development/iterations/iteration-2/04-reality-check.md
+          - 05 健康档案 UI 设计规范: development/iterations/iteration-2/05-health-record-ui-spec.md
+          - 06 埋点规划: development/iterations/iteration-2/06-experiment-tracking-plan.md
+          - 07 证据基线审计: development/iterations/iteration-2/07-evidence-baseline-audit.md
+          - 08 Git 工作流规划: development/iterations/iteration-2/08-git-workflow-plan.md
   - API:
       - 契约说明: api/index.md
   - 架构: