- FileValidationPipe now supports maxSizeByMimeType for per-MIME-type size limits
- Images: max 10MB, Video (MP4): max 100MB
- Oversized files return 413 Payload Too Large instead of 400 Bad Request
- MIME type validation runs before size check for clearer error messages
- Multer module limit raised to 100MB (per-type enforcement in pipe)
- Added 413 ApiResponse to Swagger docs on upload endpoint
- Added comprehensive unit tests for FileValidationPipe (16 test cases)
Co-Authored-By: Paperclip <noreply@paperclip.ing>