fix(lint): 修复 PR #14 引入的 lint 回退 (119→0)

PR #14 从旧分支复制文件导致回退了 PR #10 的 lint 修复。
修复内容:
- autoflake 移除未使用导入/变量
- autopep8 修复缩进/空格
- 手动修复 F821(pathlib→Path), F541(f-string), F841(未使用变量)
- 所有修复均通过 flake8 --max-line-length=120 --extend-ignore=E501 检查 (0 errors)

src/daemon/health.py

@@ -9,9 +9,9 @@ from __future__ import annotations
 import json
 import logging
 from pathlib import Path
-from typing import Any, Dict, Optional
+from typing import Any, Dict
 
-from src.blackboard.db import get_connection, init_db
+from src.blackboard.db import get_connection
 from src.blackboard.queries import Queries
 
 logger = logging.getLogger("moziplus-v2.health")
@@ -41,7 +41,7 @@ class HealthChecker:
             {"healthy": bool, "zombie": bool, "stale_ticks": int,
              "alert_written": bool, "resolved": bool}
         """
-        db_key = str(db_path)
+        str(db_path)
         result: Dict[str, Any] = {
             "healthy": True,
             "zombie": False,
@@ -58,7 +58,8 @@ class HealthChecker:
         # 用 event count 变化判断是否有真实变更
         conn = queries._conn()
         try:
-            total_events = conn.execute("SELECT COUNT(*) FROM events").fetchone()[0]
+            conn.execute(
+                "SELECT COUNT(*) FROM events").fetchone()[0]
             non_tick_events = conn.execute(
                 "SELECT COUNT(*) FROM events WHERE event_type != 'daemon_tick' "
                 "AND event_type != 'agent_zombie_detected'"
@@ -85,7 +86,8 @@ class HealthChecker:
             self._stale_ticks[project_id] = stale
             result["stale_ticks"] = stale
 
-            if stale >= self.zombie_threshold and not self._alerted.get(project_id):
+            if stale >= self.zombie_threshold and not self._alerted.get(
+                    project_id):
                 # 写告警
                 self._write_alert(db_path, project_id, tick_num, stale)
                 self._alerted[project_id] = True
@@ -126,7 +128,10 @@ class HealthChecker:
             conn.commit()
         finally:
             conn.close()
-        logger.warning("Zombie detected: %s (stale=%d)", project_id, stale_ticks)
+        logger.warning(
+            "Zombie detected: %s (stale=%d)",
+            project_id,
+            stale_ticks)
 
     def _write_resolution(self, db_path: Path, project_id: str,
                           tick_num: int) -> None: