feat(retention): 删除用户/Key 时保留历史记录，外键改 SET NULL 并添加名称快照

- Usage/RequestCandidate/VideoTask/Stats 等表的 user_id/api_key_id 外键从
  CASCADE 改为 SET NULL，删除用户或 Key 后历史记录不再丢失
- 各表添加 username/api_key_name 快照字段，删除后仍可追溯归属
- 新增 bulk_cleanup 模块，分批置空大表外键避免长事务锁
- 删除用户/Key 流程集成预清理步骤，先置空再删除
- 精简 candidate_builder 冗余 debug 日志
- 修复 proxy_nodes 启动日志 format 占位符错误（{} -> %s）
- 前端批量操作请求增加 5 分钟超时配置

src/api/admin/api_keys/routes.py

@@ -23,6 +23,7 @@ from src.database import get_db
 from src.models.api import CreateApiKeyRequest
 from src.models.database import ApiKey, Wallet
 from src.services.user.apikey import ApiKeyService
+from src.services.user.bulk_cleanup import pre_clean_api_key
 from src.services.wallet import WalletService
 
 # 应用时区配置，默认为 Asia/Shanghai
@@ -349,10 +350,7 @@ class AdminCreateStandaloneKeyAdapter(AdminApiAdapter):
         db = context.db
 
         # 独立Key支持无限制额度（initial_balance_usd = null）
-        if (
-            self.key_data.initial_balance_usd is not None
-            and self.key_data.initial_balance_usd <= 0
-        ):
+        if self.key_data.initial_balance_usd is not None and self.key_data.initial_balance_usd <= 0:
             raise HTTPException(
                 status_code=400,
                 detail="创建独立余额Key时，初始余额必须大于 0（或设置为 null 表示无限制）",
@@ -568,6 +566,7 @@ class AdminDeleteApiKeyAdapter(AdminApiAdapter):
             raise InvalidRequestException("仅支持删除独立密钥")
 
         user = api_key.user
+        pre_clean_api_key(db, api_key.id)
         db.delete(api_key)
         db.commit()
 

src/api/admin/users/routes.py

@@ -21,6 +21,7 @@ from src.models.api import CreateApiKeyRequest, CreateUserRequest
 from src.models.database import ApiKey, User, UserRole
 from src.services.system.config import SystemConfigService
 from src.services.user.apikey import ApiKeyService
+from src.services.user.bulk_cleanup import pre_clean_api_key
 from src.services.user.service import UserService
 from src.services.wallet import WalletService
 from src.utils.cache_decorator import cache_result
@@ -584,6 +585,7 @@ class AdminDeleteUserKeyAdapter(AdminApiAdapter):
         if not api_key:
             raise NotFoundException("API Key不存在或不属于该用户", "api_key")
 
+        pre_clean_api_key(db, api_key.id)
         db.delete(api_key)
         db.commit()
 

src/api/handlers/gemini/video_handler.py

@@ -634,6 +634,8 @@ class GeminiVeoHandler(VideoHandlerBase):
             external_task_id=external_task_id,
             user_id=self.user.id,
             api_key_id=self.api_key.id,
+            username=self.user.username,
+            api_key_name=self.api_key.name,
             provider_id=candidate.provider.id,
             endpoint_id=candidate.endpoint.id,
             key_id=candidate.key.id,

src/api/handlers/openai/video_handler.py

@@ -887,6 +887,8 @@ class OpenAIVideoHandler(VideoHandlerBase):
             external_task_id=external_task_id,
             user_id=self.user.id,
             api_key_id=self.api_key.id,
+            username=self.user.username,
+            api_key_name=self.api_key.name,
             provider_id=candidate.provider.id,
             endpoint_id=candidate.endpoint.id,
             key_id=candidate.key.id,
@@ -1049,6 +1051,8 @@ class OpenAIVideoHandler(VideoHandlerBase):
             external_task_id=None,
             user_id=self.user.id,
             api_key_id=self.api_key.id,
+            username=self.user.username,
+            api_key_name=self.api_key.name,
             provider_id=None,
             endpoint_id=None,
             key_id=None,

src/api/user_me/routes.py

@@ -46,6 +46,7 @@ from src.models.database import (
 from src.services.system.time_range import TimeRangeParams
 from src.services.usage.service import UsageService
 from src.services.user.apikey import ApiKeyService
+from src.services.user.bulk_cleanup import pre_clean_api_key
 from src.services.user.preference import PreferenceService
 from src.services.wallet import WalletService
 from src.utils.cache_decorator import cache_result
@@ -731,6 +732,7 @@ class DeleteMyApiKeyAdapter(AuthenticatedApiAdapter):
             raise NotFoundException("API密钥不存在", "api_key")
         if api_key.is_locked:
             raise ForbiddenException("该密钥已被管理员锁定，无法删除")
+        pre_clean_api_key(context.db, api_key.id)
         context.db.delete(api_key)
         context.db.commit()
         return {"message": "API密钥已删除"}