- Add comprehensive download queue models in src/server/models/download.py
- DownloadStatus and DownloadPriority enums for type safety
- EpisodeIdentifier for episode references
- DownloadProgress for real-time progress tracking
- DownloadItem for queue item representation with timestamps and error handling
- QueueStatus for overall queue state management
- QueueStats for aggregated queue statistics
- DownloadRequest/DownloadResponse for API contracts
- QueueOperationRequest and QueueReorderRequest for queue management
- QueueStatusResponse for complete status endpoint responses
- Add comprehensive unit tests (47 tests, all passing)
- Test validation constraints (positive numbers, ranges, etc.)
- Test default values and optional fields
- Test serialization/deserialization
- Test model relationships and nested structures
- Update documentation
- Add download models section to infrastructure.md
- Remove completed task from instructions.md
- Update models package __init__.py
All models follow PEP 8 style guide with proper type hints and validation.
