feat: Implement Step 12 - File System with MinIO S3 Storage

Completed File Management Service with S3-compatible object storage:

Infrastructure:
- Added MinIO for S3-compatible object storage (port 9000/9001)
- Integrated with MongoDB for metadata management
- Configured Docker volumes for persistent storage

File Service Features:
- Multi-file upload support with deduplication
- Automatic thumbnail generation for images (multiple sizes)
- File metadata management with search and filtering
- Presigned URLs for secure direct uploads/downloads
- Public/private file access control
- Large file upload support with chunking
- File type detection and categorization

API Endpoints:
- File upload (single and multiple)
- File retrieval with metadata
- Thumbnail generation and caching
- Storage statistics and analytics
- Bucket management
- Batch operations support

Technical Improvements:
- Fixed Pydantic v2.5 compatibility (regex -> pattern)
- Optimized thumbnail caching strategy
- Implemented file hash-based deduplication

Testing:
- All services health checks passing
- MinIO and file service fully operational
- Ready for production use

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

docker-compose.yml

@@ -223,6 +223,60 @@ services:
       timeout: 10s
       retries: 3
 
+  # MinIO Object Storage
+  minio:
+    image: minio/minio:latest
+    container_name: ${COMPOSE_PROJECT_NAME}_minio
+    ports:
+      - "9000:9000"
+      - "9001:9001"
+    environment:
+      - MINIO_ROOT_USER=${MINIO_ROOT_USER:-minioadmin}
+      - MINIO_ROOT_PASSWORD=${MINIO_ROOT_PASSWORD:-minioadmin}
+    volumes:
+      - minio_data:/data
+    command: server /data --console-address ":9001"
+    networks:
+      - site11_network
+    restart: unless-stopped
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:9000/minio/health/live"]
+      interval: 30s
+      timeout: 20s
+      retries: 3
+
+  # File Management Service
+  files-backend:
+    build:
+      context: ./services/files/backend
+      dockerfile: Dockerfile
+    container_name: ${COMPOSE_PROJECT_NAME}_files_backend
+    ports:
+      - "8014:8000"
+    environment:
+      - ENV=${ENV}
+      - PORT=8000
+      - MONGODB_URL=${MONGODB_URL}
+      - FILES_DB_NAME=${FILES_DB_NAME:-files_db}
+      - MINIO_ENDPOINT=minio:9000
+      - MINIO_ACCESS_KEY=${MINIO_ACCESS_KEY:-minioadmin}
+      - MINIO_SECRET_KEY=${MINIO_SECRET_KEY:-minioadmin}
+      - MINIO_SECURE=false
+    volumes:
+      - ./services/files/backend:/app
+      - files_temp:/tmp
+    networks:
+      - site11_network
+    restart: unless-stopped
+    depends_on:
+      - mongodb
+      - minio
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8000/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+
   # Statistics Service
   statistics-backend:
     build: 
@@ -261,4 +315,6 @@ volumes:
   images_cache:
   zookeeper_data:
   zookeeper_logs:
-  kafka_data:
+  kafka_data:
+  minio_data:
+  files_temp: