fix(proxy): register TokenUsageService in ProxyModule providers

src/server/modules/proxy/proxy.module.ts

@@ -5,11 +5,12 @@ import { TokenManagerService } from './token-manager.service';
 import { GeminiClient } from './clients/gemini.client';
 import { GeminiController } from './gemini.controller';
 import { ProxyGuard } from './proxy.guard';
+import { TokenUsageService } from '../usage/token-usage.service';
 
 @Module({
   imports: [],
   controllers: [ProxyController, GeminiController],
-  providers: [ProxyService, TokenManagerService, GeminiClient, ProxyGuard],
+  providers: [ProxyService, TokenManagerService, GeminiClient, ProxyGuard, TokenUsageService],
   exports: [TokenManagerService],
 })
 export class ProxyModule {}