fix(skills): replace polling/pre-spawning with Stop-Wait pattern across all team coordinators

All team coordinator roles now follow the Stop-Wait design principle:
- Phase 2: Remove worker pre-spawning, workers are spawned per-stage in Phase 4
- Phase 4: Add Stop-Wait principle note (synchronous Task calls instead of polling)
- monitor.md: Replace while+sleep polling loops with synchronous Task execution

Teams updated: team-brainstorm, team-frontend, team-issue, team-iterdev,
team-lifecycle, team-lifecycle-v2, team-quality-assurance, team-tech-debt,
team-testing, team-uidesign, team-ultra-analyze

.claude/skills/team-iterdev/roles/coordinator.md

@@ -112,7 +112,9 @@ const teamSession = {
 Write(`${sessionFolder}/team-session.json`, JSON.stringify(teamSession, null, 2))
 ```
 
-Spawn workers (see SKILL.md Coordinator Spawn Template).
+// ⚠️ Workers are NOT pre-spawned here.
+// Workers are spawned per-stage in Phase 4 via Stop-Wait Task(run_in_background: false).
+// See SKILL.md Coordinator Spawn Template for worker prompt templates.
 
 ### Phase 3: Create Task Chain + Update Ledger
 
@@ -161,6 +163,13 @@ TaskUpdate({ taskId: reviewId, owner: "reviewer", addBlockedBy: [devId] })
 
 ### Phase 4: Coordination Loop + GC Control + Ledger Updates
 
+> **设计原则（Stop-Wait）**: 模型执行没有时间概念，禁止任何形式的轮询等待。
+> - ❌ 禁止: `while` 循环 + `sleep` + 检查状态
+> - ✅ 采用: 同步 `Task(run_in_background: false)` 调用，Worker 返回 = 阶段完成信号
+>
+> 按 Phase 3 创建的任务链顺序，逐阶段 spawn worker 同步执行。
+> Worker prompt 使用 SKILL.md Coordinator Spawn Template。
+
 | Received Message | Action |
 |-----------------|--------|
 | architect: design_ready | Read design → update ledger → unblock DEV |