修复任务卡死与安能启动失败

- runtime.py: launch_anneng 拉起前清除 NODE_OPTIONS，避免 Electron 因 --use-system-ca 启动即退出(rc=9)
- server.py: POST /tasks 在 worker 未就绪时返回 409 拦截误操作；worker 就绪后调用 fail_stale_tasks 实现重启自愈
- state_store.py: 新增 fail_stale_tasks()，将遗留 pending/running 任务标记为 failed

state_store.py

@@ -426,3 +426,16 @@ def list_tasks(limit=20):
         }
         for r in rows
     ]
+
+
+def fail_stale_tasks(reason: str = "服务重启，上轮未完成任务，请手动重跑") -> int:
+    """worker 启动时调用：把遗留的 pending/running 任务标记为 failed，实现重启自愈。
+    返回被清理的任务数量。"""
+    with sqlite3.connect(STATE_DB_PATH) as conn:
+        cur = conn.execute(
+            "UPDATE task_history SET status=?, finished_at=?, error=? "
+            "WHERE status IN (?, ?)",
+            (TASK_FAILED, _now(), reason, TASK_PENDING, TASK_RUNNING),
+        )
+        conn.commit()
+        return cur.rowcount