feat(api-key): add independent quota and expiration support

This feature allows API Keys to have their own quota limits and expiration
times, independent of the user's balance.

Backend:
- Add quota, quota_used, expires_at fields to api_key schema
- Implement IsExpired() and IsQuotaExhausted() checks in middleware
- Add ResetQuota and ClearExpiration API endpoints
- Integrate quota billing in gateway handlers (OpenAI, Anthropic, Gemini)
- Include quota/expiration fields in auth cache for performance
- Expiration check returns 403, quota exhausted returns 429

Frontend:
- Add quota and expiration inputs to key create/edit dialog
- Add quick-select buttons for expiration (+7, +30, +90 days)
- Add reset quota confirmation dialog
- Add expires_at column to keys list
- Add i18n translations for new features (en/zh)

Migration:
- Add 045_add_api_key_quota.sql for new columns

backend/internal/service/openai_gateway_service.go

@@ -1681,13 +1681,14 @@ func (s *OpenAIGatewayService) replaceModelInResponseBody(body []byte, fromModel
 
 // OpenAIRecordUsageInput input for recording usage
 type OpenAIRecordUsageInput struct {
-	Result       *OpenAIForwardResult
-	APIKey       *APIKey
-	User         *User
-	Account      *Account
-	Subscription *UserSubscription
-	UserAgent    string // 请求的 User-Agent
-	IPAddress    string // 请求的客户端 IP 地址
+	Result        *OpenAIForwardResult
+	APIKey        *APIKey
+	User          *User
+	Account       *Account
+	Subscription  *UserSubscription
+	UserAgent     string // 请求的 User-Agent
+	IPAddress     string // 请求的客户端 IP 地址
+	APIKeyService APIKeyQuotaUpdater
 }
 
 // RecordUsage records usage and deducts balance
@@ -1799,6 +1800,13 @@ func (s *OpenAIGatewayService) RecordUsage(ctx context.Context, input *OpenAIRec
 		}
 	}
 
+	// Update API key quota if applicable (only for balance mode with quota set)
+	if shouldBill && cost.ActualCost > 0 && apiKey.Quota > 0 && input.APIKeyService != nil {
+		if err := input.APIKeyService.UpdateQuotaUsed(ctx, apiKey.ID, cost.ActualCost); err != nil {
+			log.Printf("Update API key quota failed: %v", err)
+		}
+	}
+
 	// Schedule batch update for account last_used_at
 	s.deferredService.ScheduleLastUsedUpdate(account.ID)