feat(agent): L2/L4 记忆注入——项目规范 + 全局规范文件喂进 4 处 prompt

- L2 projects.agent_rules 列（schema+迁移+类型+mapper+patchProject+API 透传）
- L4 protocol.readGlobalAgentRules()：worker 直接读 <data>/agent-global.md（非DB，
  不读用户 ~/.claude/CLAUDE.md，避免个人习惯与受控执行冲突）
- runner.rulesHeaderLines 注入 executor/planner/conflict；reviewer 同注入
- 顺序：全局规范(L4)→项目规范(L2)→任务内容→上次失败(L1)→执行约束

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/api/server.ts

@@ -101,6 +101,7 @@ export function buildServer(opts: ApiOptions): FastifyInstance {
     if (b.autoApprovePlan !== undefined) patch.autoApprovePlan = Boolean(b.autoApprovePlan);
     if (b.autoApproveExec !== undefined) patch.autoApproveExec = Boolean(b.autoApproveExec);
     if (b.checks !== undefined) patch.checks = b.checks === null || b.checks === '' ? null : String(b.checks);
+    if (b.agentRules !== undefined) patch.agentRules = b.agentRules === null || b.agentRules === '' ? null : String(b.agentRules);
     return projectOut(store.patchProject(id, patch));
   });