- upstream._get: one 300ms retry on transient errors (CF 403/503, 429,
5xx); 404 stays final. Fixes the 502 cluster that hls.js couldn't
recover from (fragLoadTimeOut x3 in error log)
- /stream: upstream timeout 12s < hls.js fragLoadingTimeOut (20s), so a
hung segment 502s first and hls.js retries instead of fatal-timing-out
- /stream responses: Cache-Control public max-age=86400 (VOD + token is
the exact upstream URL => immutable); re-opens/re-seeks skip the proxy
- /api/stream: drop unused qualities (frontend never read it; saved a
~0.2s cold upstream round-trip per episode)
- app.js/style.css: max-age=300 instead of no-store
- test_history_page_and_delete: stale selector (home redesign removed
the 'view all' link; use 'history ->')