- Graceful shutdown: SIGTERM/SIGINT handlers stop continuous scraper,
disconnect Telegram client, drain running jobs with timeout
- Logging: replace print() with logging module throughout web server,
basicConfig in main.py with structured log format
- Streaming: chunked file reads (64KB) instead of loading entire files
into memory; full HTTP Range Request support (206 Partial Content)
for video seeking in the browser
- Cache: TTL-based in-memory cache (1s) for state.json reads in
StateStore, thread-safe with existing RLock
- Bugfix: send_error_json now converts HTTPStatus to int for JSON
forust