Implement video transcoding pipeline

Add video transcoding for multiple quality levels and formats.

Requirements:

• Input: various video formats (MP4, AVI, MOV, etc.)
• Output: HLS adaptive streaming (multiple bitrates)
• Quality levels: 1080p, 720p, 480p, 360p

Implementation Stack:

• FFmpeg for transcoding
• S3/MinIO for storage
• Message queue (RabbitMQ/Kafka) for job processing
• Progress tracking and notifications

Tasks:

• Set up FFmpeg worker service
• Implement transcoding job queue
• Add progress tracking
• Store transcoded files
• Update catalog with transcoded URLs
• Add thumbnail generation