fix: 修复实际使用中发现的 4 个 bug

- todo_parser: 支持无方括号的短 ID 提取（G-001/H-000 格式）
  原来只认 [T-xxx] 方括号格式，非方括号行退化为全文当 ID
- arc_mode: parallel_review_mode 保留 arcPhase 字段
  原来写 state 时覆盖为 {enabled, updatedAt, projectRoot}，丢失 phase
- airplan.py: 新增 --task-text CLI 参数
  原来 argparse 缺此参数，do 模式无法接收任务描述
- do_mode.main: 透传 task_text 给 enter_worker
  原来调 enter_worker(project_root, tid) 缺第三个参数
  P1-20 is_ui_task() 永远收到空字符串

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lib/air_runtime/modes/arc_mode.py

@@ -249,8 +249,11 @@ def parallel_review_mode(project_root: Path, todo_path: Path) -> dict:
         markdown_lines.append(f"- `{g.name}`: {', '.join(g.task_ids)} — {g.reason}")
     paths["execution_plan_md"].write_text("\n".join(markdown_lines) + "\n", encoding="utf-8")
 
-    atomic_json_write(paths["state"], {"enabled": True, "updatedAt": now_iso(),
-                                        "projectRoot": str(project_root)})
+    # 保留 arcPhase 字段，避免 phase 被 reset 为 discussing
+    existing_state = safe_json_load(paths["state"]) or {}
+    state_payload = {**existing_state, "enabled": True, "updatedAt": now_iso(),
+                     "projectRoot": str(project_root)}
+    atomic_json_write(paths["state"], state_payload)
     return {"json_path": str(review_json_path), "markdown_path": str(review_md_path),
             "execution_plan_json_path": str(paths["execution_plan_json"]),
             "parallel_group_count": len(review.parallel_groups),

lib/air_runtime/modes/do_mode.py

@@ -244,7 +244,8 @@ def main(args) -> None:
         print(f"active_task_id={s['activeTaskId']}")
         print(f"known_tasks={','.join(s['taskIds'])}")
     elif sub == "enter":
-        result = enter_worker(project_root, tid)
+        task_text = getattr(args, "task_text", "") or ""
+        result = enter_worker(project_root, tid, task_text=task_text)
         print("airplan_mode=do")
         print(f"task_id={result['taskId']}")
         print(f"brief_path={result['briefPath']}")