feat: security hardening, streaming overhaul, design polish, tests

Security:
- Replace unsalted SHA-256 password hashing with bcrypt (lazy rehash on login)
- Add authenticated /api/xtream-api gateway: Xtream credentials are injected
  server-side and never sent to the frontend; /api/playlists no longer
  returns passwords
- Redact credentials from all logs (login body, proxy/FFmpeg/scheduler URLs)
- Add auth to recordings, EPG, season-passes and streaming routes
  (HttpOnly session cookie for hls.js; loopback bypass for local FFmpeg)
- Lock player postMessage to same-origin in both directions
- Vendor and pin hls.js 1.6.7 / mpegts.js 1.7.3 (drop CDN @latest)
- Fix rate limiter (client IP was never resolved), add login rate limit,
  restrict CORS, add CSP Report-Only, block private-IP SSRF targets,
  fix path traversal in recording log retrieval, chmod 777 -> 770
- Remove dead HiveService (seeded admin/admin into IndexedDB with SHA-256)
- Fix authMiddleware not populating 'user' context (getPlaylist ignored the
  logged-in user; admin purge always returned 403)

Streaming:
- New FfmpegSessionManager: process registry, idle reaper (4 min live /
  15 min VOD), orphan cleanup at startup, clean SIGTERM shutdown,
  fast-fail with stderr instead of 30 s timeout
- Quality selection (source/high/medium/low) for live and VOD; source mode
  streams with -c:v copy (zero transcoding); selector wired into the player
- Concurrent recordings (MAX_CONCURRENT_RECORDINGS, default 2); conflicts
  retry on the next tick instead of silently failing
- Lower live latency (HLS window 20 -> 10 segments, liveSync 10 -> 3)
- Fix recording log lookup (.mp4 vs .mkv mismatch)

Design:
- Replace hardcoded colors with AppColors tokens (12 files)
- web/theme.css syncs HTML players with the Flutter palette
- DPAD/keyboard navigation (arrow-key focus, player shortcuts)
- Tooltips on player icon buttons, Semantics on content cards
- Remove 7 dead widgets broken since the Stitch merge

Quality:
- bin/test/: 21 unit tests (bcrypt, redaction, traversal, SSRF, recording
  conflicts) plus a quality-selector widget test
- GitHub Actions CI (analyze + test + build web)
- Archive stale status docs into docs/archive/

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/theme.css

@@ -0,0 +1,14 @@
+/* XtremFlow web player theme tokens.
+   Mirrors lib/core/theme/app_colors.dart (Cyber-Cinematic Glass).
+   Keep both files in sync when the palette changes. */
+:root {
+    --color-bg: #0F1014;            /* AppColors.baseLevel0 */
+    --color-surface: #121317;       /* AppColors.surface */
+    --color-text: #e3e2e7;          /* AppColors.textPrimary */
+    --color-text-secondary: #c1c6d7;/* AppColors.textSecondary */
+    --color-accent: #adc6ff;        /* AppColors.primary */
+    --color-accent-strong: #4b8eff; /* AppColors.primaryContainer */
+    --color-error: #ffb4ab;         /* AppColors.error */
+    --color-overlay: rgba(15, 16, 20, 0.6);
+    --color-border: rgba(255, 255, 255, 0.1); /* glassLevel1Border */
+}