Feature: Extend server to support file handling capabilities

[k5101998]

@mykolasolodukha Here is Proposed Architecture and basic Implementation. Please have a look at it and let me know your thoughts. Thanks.

1. File Storage Service Layer

• Extend the existing BaseStorageService to handle general files, not just images
• Support multiple storage backends (S3, Azure Blob Storage, Local FileSystem)
• Implement chunked file uploads for large files
• Add file metadata handling (size, type, created date, etc.)

2. API Endpoints

• /api/files/upload - For file uploads (multipart/form-data)
• /api/files/download/{file_id} - For file downloads
• /api/files/{file_id} - For file metadata
• /api/files - For listing files

3. Database Schema

• Create a new File model to store file metadata
• Include fields for: id, filename, size, mime_type, storage_location, created_at, etc.

4. Security & Performance

• Implement file type validation
• Add file size limits
• Use streaming responses for large files
• Add rate limiting
• Implement authentication/authorization

TODO:

1. Implement Cloud Storage

• Add S3 storage implementation
• Add Azure Blob storage implementation
• Implement URL signing for direct downloads

2. Add Advanced Features

• File type detection

3. Add authentication/authorization

• Implement rate limiting
• Add file encryption
• Set up CORS policies

4. Performance Optimizations

• Add caching layer
• Implement background processing for large files
• Add compression