fix: 修复 mypy 类型检查错误并升级到 Python 3.14

主要变更：
- 修复 1483 个 mypy 类型检查错误
- 添加缺失的类型注解 (Any, Callable, Session 等)
- 修复隐式 Optional 类型 (param: Type = None -> param: Type | None = None)
- 修复 __new__ 单例模式返回类型
- 添加 type: ignore 注释处理第三方库类型问题
- 更新 pyproject.toml 依赖到 Python 3.14 兼容版本
- 更新 mypy/black 配置为 Python 3.14

src/api/base/authenticated_adapter.py

@@ -1,3 +1,4 @@
+from src.api.base.context import ApiRequestContext
 from fastapi import HTTPException
 
 from .adapter import ApiAdapter, ApiMode
@@ -8,6 +9,6 @@ class AuthenticatedApiAdapter(ApiAdapter):
 
     mode = ApiMode.USER
 
-    def authorize(self, context):  # type: ignore[override]
+    def authorize(self, context: ApiRequestContext) -> None:  # type: ignore[override]
         if not context.user:
             raise HTTPException(status_code=401, detail="未登录")

src/api/base/pipeline.py

@@ -54,7 +54,7 @@ class ApiRequestPipeline:
         mode: ApiMode = ApiMode.STANDARD,
         api_format_hint: str | None = None,
         path_params: dict[str, Any] | None = None,
-    ):
+    ) -> Any:
         # 高频轮询端点抑制 debug 日志
         is_quiet = http_request.url.path in QUIET_POLLING_PATHS
         if not is_quiet:
@@ -500,7 +500,7 @@ class ApiRequestPipeline:
 
         return self._sanitize_metadata(metadata)
 
-    def _sanitize_metadata(self, value: Any, depth: int = 0):
+    def _sanitize_metadata(self, value: Any, depth: int = 0) -> None:
         if value is None:
             return None
         if depth > 5: