refactor: 全局适配 ApiFamily/EndpointKind 结构化标识体系

将新的 (ApiFamily, EndpointKind) / `family:kind` 签名体系应用到整个代码库：
- API Handlers: 所有 adapter/handler 使用新的签名格式
- Services: provider, model, usage, cache, auth 等服务层适配
- Database: ProviderEndpoint 新增 api_family/endpoint_kind 字段
- Frontend: Provider 管理、Usage 表格等组件适配
- Tests: 更新所有相关测试用例

tests/services/test_auth.py

@@ -7,20 +7,20 @@
 - API Key 认证
 """
 
-import pytest
 from datetime import datetime, timedelta, timezone
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import jwt
+import pytest
 
-from src.services.auth.service import (
-    AuthService,
-    JWT_SECRET_KEY,
-    JWT_ALGORITHM,
-    JWT_EXPIRATION_HOURS,
-)
 from src.core.enums import AuthSource
 from src.models.database import UserRole
+from src.services.auth.service import (
+    JWT_ALGORITHM,
+    JWT_EXPIRATION_HOURS,
+    JWT_SECRET_KEY,
+    AuthService,
+)
 
 
 class TestJWTTokenCreation: