chore: simayi-approved changes - lint fixes, toolchain improvements, healthz

All changes reviewed and APPROVED in PR #12 (Review ID: 40):
- toolchain_routes: webhook repo/org format compat, content dedup (sha256), closed issue filter
- dispatcher: inform mail crash 误标 done 修复
- ticker: cleanup and improvements
- healthz endpoint
- conftest: integration/e2e deselect markers
- docs: design docs, test-guide updates
- various lint/whitespace fixes across 30 files

src/daemon/inbox.py

@@ -15,6 +15,7 @@ from __future__ import annotations
 import asyncio
 import json
 import logging
+import os
 from pathlib import Path
 from typing import Any, Callable, Coroutine, Dict, List, Optional
 
@@ -56,7 +57,7 @@ class InboxWatcher:
         self._running = True
         self._task = asyncio.create_task(self._loop())
         logger.info("Inbox watcher started (path=%s, interval=%.1fs)",
-                    self.inbox_path, self.watch_interval)
+                     self.inbox_path, self.watch_interval)
 
     async def stop(self) -> None:
         """停止监听"""
@@ -68,7 +69,7 @@ class InboxWatcher:
             except asyncio.CancelledError:
                 pass
         logger.info("Inbox watcher stopped (processed=%d, errors=%d)",
-                    self._total_processed, self._total_errors)
+                     self._total_processed, self._total_errors)
 
     @property
     def is_running(self) -> bool: