chore(task): M4 任务收尾——review 修复 P0/P1/P2 全收口,标 completed

M1-M4 全量 review backlog(P0 主流程/P1 稳健性/P2 spec 回填)已全数修完,
263 测试绿 + CI 双平台绿(run 28422981875)。任务标 completed。

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

.trellis/tasks/06-27-m4-ai-roles/task.json

@@ -3,7 +3,7 @@
   "name": "m4-ai-roles",
   "title": "M4 AI 角色层与一级宿主壳",
   "description": "",
-  "status": "in_progress",
+  "status": "completed",
   "dev_type": null,
   "scope": null,
   "package": null,
@@ -11,7 +11,7 @@
   "creator": "codex",
   "assignee": "codex",
   "createdAt": "2026-06-27",
-  "completedAt": null,
+  "completedAt": "2026-06-30",
   "branch": null,
   "base_branch": "v7",
   "worktree_path": null,