- Recover completed .part files on HTTP 416 without deleting and redownloading
- Add stream stall detection and automatic reconnect for interrupted socket reads
- Implement persistent download state store and pause/resume lifecycle controls
- Add RateLimitCoordinator and ConnectivityGuard circuit breaker for requests
- Support proxy_url configuration and validate aria2 proxy settings
- Add unit tests for 416 recovery, stall reconnect, state store, and network guard
- Drain aria2 daemon stderr in a background thread to prevent Windows pipe buffer saturation and deadlock
- Promote critical disk write and permission errors from aria2 stderr to warnings
- Automatically refresh expired signed CDN URLs and resume downloads via aria2 continue=true
- Shield addUri against mid-registration cancellations to prevent orphaned downloads
- Retry Range requests directly on target URL when redirects drop the Range header in Python downloads
- Add auto-reconnect stream loop on transient socket disruptions with seamless partial-hash resumption
- Increase default download chunk size to 4MB for improved I/O throughput
- Parse HTTP 429 Retry-After headers for informative rate limit reporting
- Add unit test suite covering new aria2 and Python downloader resilience behaviors
- Omit blocking checksum and check-integrity options from aria2 transfers to prevent long pauses at 100% on large models
- Run SHA-256 integrity verification asynchronously in a background thread via Python hashlib
- Update download progress and metadata sidecars upon background verification completion or mismatch
- Add unit tests for aria2 option omission and background verification
Dariusz L