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_error_classifier_thinking.py

@@ -94,9 +94,7 @@ class TestThinkingErrorPatterns:
         error = '{"error": {"message": "expected redacted_thinking, found text"}}'
         assert classifier._is_thinking_error(error) is True
 
-    def test_detect_expected_redacted_thinking_backticks(
-        self, classifier: ErrorClassifier
-    ) -> None:
+    def test_detect_expected_redacted_thinking_backticks(self, classifier: ErrorClassifier) -> None:
         """检测带反引号的 expected redacted_thinking 错误"""
         error = '{"error": {"message": "expected `redacted_thinking`, found `text`"}}'
         assert classifier._is_thinking_error(error) is True