feat: add MediaModule with service for virus scanning and media processing

Introduced MediaModule with MediaService to handle antivirus scanning using ClamAV and media file processing for images (webp/avif) and videos (webm/av1). Includes media-related interfaces and module exports for broader application integration.

backend/src/media/media.module.ts

@@ -0,0 +1,8 @@
+import { Module } from "@nestjs/common";
+import { MediaService } from "./media.service";
+
+@Module({
+	providers: [MediaService],
+	exports: [MediaService],
+})
+export class MediaModule {}