feat(design): Warm Cinema theme + event-driven adaptive players

Replaces the Projector Noir palette with "Warm Cinema" and rebuilds the
web players around a shared, event-driven engine.

Design
- app_colors: warm charcoal (#0B0908), cream (#F3E9DF), ember (#D9541F);
  adds posterScrim/heroScrim gradients, lift()/emberFocus() shadows,
  const cream-alpha tokens replacing Colors.whiteNN, and primaryFill,
  a deeper ember reserved for text-bearing fills so white labels clear
  the 4.5:1 AA threshold that #D9541F alone does not
- app_theme / mobile_theme: Fraunces (display serif) + Karla (body),
  tighter radii, 20+ component themes
- glass_container: opaque layered surfaces replace the blurred glass
- themed_loading_screen restyled; players and boot splash follow

Performance
- drop every BackdropFilter: backdrop blur forced a full framebuffer
  read per frame per card, the main source of scroll jank
- bundle Fraunces/Karla as assets so google_fonts stops fetching from
  fonts.gstatic.com at startup
- bound image decode size on 12 sites: a 40-poster grid drops from
  ~240 MB to a few tens of MB of GPU memory

Players (new shared engine: web/xf-player-core.js)
- start on media events instead of polling the buffer every 100-200 ms
- hls.js/mpegts.js loaded on demand, so ~213 KB of mpegts is never
  fetched for HLS streams
- liveSyncDurationCount 10 -> 2, startFragPrefetch on, testBandwidth
  off, MPEG-TS initial stash 512 KB -> 64 KB
- adaptive escalation fast -> balanced -> safe after repeated stalls in
  a 60 s window, applied live for HLS so there is no visible cut

Preserved from the recent streaming work on main: server-side quality
selection, stable player viewId, the turbo direct MPEG-TS path, vendored
library cache headers and the CI/Docker changes. Only the theme layer and
the player front-end were replaced; GlassCard stays in ui_components.

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

lib/features/iptv/widgets/series_tab.dart

@@ -199,7 +199,7 @@ class _SeriesTabState extends ConsumerState<SeriesTab> {
                   children: [
                     Text(
                       'TV Series',
-                      style: GoogleFonts.syne(
+                      style: GoogleFonts.fraunces(
                         fontSize: 24,
                         fontWeight: FontWeight.w700,
                         color: AppColors.onSurface,
@@ -229,14 +229,14 @@ class _SeriesTabState extends ConsumerState<SeriesTab> {
                           Expanded(
                             child: TextField(
                               controller: _searchController,
-                              style: GoogleFonts.instrumentSans(
+                              style: GoogleFonts.karla(
                                 fontSize: 14,
                                 color: AppColors.onSurface,
                               ),
                               decoration: InputDecoration(
                                 hintText: 'Search series...',
                                 hintStyle:
-                                    GoogleFonts.instrumentSans(color: AppColors.outline),
+                                    GoogleFonts.karla(color: AppColors.outline),
                                 border: InputBorder.none,
                                 isDense: true,
                                 contentPadding:
@@ -344,6 +344,8 @@ class _SeriesTabState extends ConsumerState<SeriesTab> {
                               ? Image.network(
                                   _getProxiedImageUrl(serie.cover),
                                   fit: BoxFit.cover,
+                                  cacheWidth: 400,
+                                  filterQuality: FilterQuality.low,
                                   errorBuilder: (ctx, err, stack) => Container(
                                     color: AppColors.surfaceContainerLow,
                                     child: Center(
@@ -397,7 +399,7 @@ class _SeriesTabState extends ConsumerState<SeriesTab> {
                           bottom: 12,
                           child: Text(
                             serie.name,
-                            style: GoogleFonts.instrumentSans(
+                            style: GoogleFonts.karla(
                               color: AppColors.onSurface,
                               fontSize: 13,
                               fontWeight: FontWeight.w600,
@@ -440,7 +442,7 @@ class _SeriesTabState extends ConsumerState<SeriesTab> {
                                   const SizedBox(width: 4),
                                   Text(
                                     _formatRating(serie.rating)!,
-                                    style: GoogleFonts.instrumentSans(
+                                    style: GoogleFonts.karla(
                                       fontSize: 10,
                                       fontWeight: FontWeight.bold,
                                       color: AppColors.onSurface,