feat: add smoke tests, agent credit ledger, and player cashback page

Introduce admin smoke-test suite with API probes, agent credit transaction history, and player cashback records; fix SmokeTestModule DI and polish admin/player UI assets.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/src/main.ts

@@ -2,17 +2,16 @@ import { NestFactory } from '@nestjs/core';
 import { ValidationPipe } from '@nestjs/common';
 import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
 import { NestExpressApplication } from '@nestjs/platform-express';
-import { join } from 'path';
 import { AppModule } from './app.module';
 import { GlobalExceptionFilter } from './shared/common/filters';
+import { getUploadRoot } from './shared/uploads/upload-paths';
 
 async function bootstrap() {
   const app = await NestFactory.create<NestExpressApplication>(AppModule);
   app.enableShutdownHooks();
   app.useGlobalFilters(new GlobalExceptionFilter());
 
-  const uploadDir = process.env.UPLOAD_DIR || join(__dirname, '..', '..', 'uploads');
-  app.useStaticAssets(uploadDir, { prefix: '/uploads/' });
+  app.useStaticAssets(getUploadRoot(), { prefix: '/uploads/' });
 
   app.setGlobalPrefix('api');
   app.enableCors({ origin: true, credentials: true });