feat: hot reload for config/templates and GitPython-based hot update with pre-update notification

templates.py

@@ -1,11 +1,12 @@
 """模板渲染：从 templates/ 目录加载 .txt 模板并用 str.format 填充。
 
 查找顺序：本模块所在目录、当前工作目录。
+文件按修改时间自动热重载，改动后无需重启。
 """
 from pathlib import Path
 
 _CANDIDATE_DIRS = [Path(__file__).parent / "templates", Path("templates")]
-_cache: dict[str, str] = {}
+_cache: dict[str, tuple[float, str]] = {}  # name -> (mtime, content)
 
 
 def _dir() -> Path:
@@ -16,6 +17,9 @@ def _dir() -> Path:
 
 
 def render(name: str, **kwargs) -> str:
-    if name not in _cache:
-        _cache[name] = (_dir() / f"{name}.txt").read_text(encoding="utf-8")
-    return _cache[name].format(**kwargs)
+    path = _dir() / f"{name}.txt"
+    mtime = path.stat().st_mtime
+    cached = _cache.get(name)
+    if cached is None or cached[0] != mtime:
+        _cache[name] = (mtime, path.read_text(encoding="utf-8"))
+    return _cache[name][1].format(**kwargs)