feat: enhance configuration and rate limiting

- Added new configuration options: trustProxy, uploadConcurrency, batchMaxItems, batchMaxSizeBytes, and maxRequestBodyBytes to AppConfig.
- Implemented utility functions for parsing environment variables and masking sensitive data.
- Updated rate limiting logic to use configurable window size and maximum requests per window.
- Introduced a middleware for rate limiting on specific routes.
- Refactored file handling routes to support streaming downloads instead of redirects.
- Improved error handling and response formatting in file routes.
- Added support for oversized request rejection based on Content-Length header.
- Updated Swagger documentation to reflect changes in API behavior and responses.
- Enhanced tests to cover new features and ensure proper functionality.

src/index.ts

@@ -6,19 +6,19 @@ import { handleHealth } from './routes/health';
 import { handleSwaggerHtml, handleSwaggerJson } from './routes/swagger';
 import { handleUpload } from './routes/upload';
 import logger from './utils/logger';
-import { cleanupRateLimitCache } from './utils/rateLimit';
+import { cleanupRateLimitCache, withRateLimit } from './utils/rateLimit';
 
 const server = serve({
   port: config.port,
   routes: {
     '/api/upload': {
-      POST: handleUpload,
+      POST: withRateLimit(handleUpload),
     },
     '/f/:public_id': {
-      GET: handleFileRedirect,
+      GET: withRateLimit(handleFileRedirect),
     },
     '/file/:public_id/info': {
-      GET: handleFileInfo,
+      GET: withRateLimit(handleFileInfo),
     },
     '/health': {
       GET: handleHealth,