feat(s3): enhance logging and public URL generation

Add detailed logging for S3 uploads in user and content services. Improve public URL generation logic in `S3Service` by providing better handling for `API_URL`, `DOMAIN_NAME`, and `PORT`. Update relevant tests to cover all scenarios.

backend/src/users/users.service.ts

@@ -143,6 +143,7 @@ export class UsersService {
 		// 3. Upload vers S3
 		const key = `avatars/${uuid}/${Date.now()}-${uuidv4()}.${processed.extension}`;
 		await this.s3Service.uploadFile(key, processed.buffer, processed.mimeType);
+		this.logger.log(`Avatar uploaded successfully to S3: ${key}`);
 
 		// 4. Mise à jour de la base de données
 		const user = await this.update(uuid, { avatarUrl: key });