feat: implement ContentsModule with controllers, services, and DTOs

Added a new ContentsModule to handle content creation, upload, and management. Includes controller endpoints for CRUD operations, content exploration, and tagging. Integrated caching, file processing, S3 storage, and database logic.

backend/src/contents/contents.module.ts

@@ -0,0 +1,15 @@
+import { Module } from "@nestjs/common";
+import { AuthModule } from "../auth/auth.module";
+import { CryptoModule } from "../crypto/crypto.module";
+import { DatabaseModule } from "../database/database.module";
+import { MediaModule } from "../media/media.module";
+import { S3Module } from "../s3/s3.module";
+import { ContentsController } from "./contents.controller";
+import { ContentsService } from "./contents.service";
+
+@Module({
+	imports: [DatabaseModule, S3Module, AuthModule, CryptoModule, MediaModule],
+	controllers: [ContentsController],
+	providers: [ContentsService],
+})
+export class ContentsModule {}