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/core/widgets/glass_container.dart

@@ -1,12 +1,19 @@
-import 'dart:ui';
 import 'package:flutter/material.dart';
 import '../theme/app_colors.dart';
 
-/// Glassmorphism container with 3 depth levels (Stitch Design System)
+/// Conteneur de surface « Warm Cinema » — 3 niveaux de profondeur.
 ///
-/// Level 0: Pure base background (#0F1014), no blur.
-/// Level 1: Translucent layer with backdrop blur 20px, 1px border 10% white.
-/// Level 2: High-blur floating container with subtle inner glow in primary accent.
+/// Level 0 : socle brut (#0B0908), aucune ombre.
+/// Level 1 : plaque opaque légèrement éclaircie, liseré crème 8 %, ombre douce.
+/// Level 2 : bloc flottant, liseré ember sur l'arête haute, ombre profonde.
+///
+/// PERF : cette version n'utilise **aucun** `BackdropFilter`. Le flou de fond
+/// forçait Flutter Web à relire le framebuffer à chaque frame pour chaque
+/// carte à l'écran (33 sites d'appel ici) — cause principale du jank au
+/// scroll. La profondeur est désormais rendue par des surfaces opaques
+/// pré-teintées et des ombres, ce qui coûte quasiment rien au GPU.
+///
+/// L'API publique est inchangée : aucun site d'appel n'a besoin d'être modifié.
 enum GlassLevel { level0, level1, level2 }
 
 class GlassContainer extends StatelessWidget {
@@ -21,6 +28,14 @@ class GlassContainer extends StatelessWidget {
   final bool border;
   final List<BoxShadow>? boxShadow;
 
+  /// Alias de [border] (nom utilisé par les widgets de navigation TV).
+  /// Prioritaire sur [border] lorsqu'il est fourni.
+  final bool? hasBorder;
+
+  /// Passer `false` supprime toute ombre portée — utile pour les barres
+  /// collées à un bord, où l'ombre créerait une couture visible.
+  final bool showShadow;
+
   const GlassContainer({
     super.key,
     required this.child,
@@ -28,14 +43,18 @@ class GlassContainer extends StatelessWidget {
     this.height,
     this.padding = const EdgeInsets.all(16),
     this.margin,
-    this.borderRadius = 16.0,
+    this.borderRadius = 14.0,
     this.level = GlassLevel.level1,
     this.borderColor,
     this.border = true,
     this.boxShadow,
+    this.hasBorder,
+    this.showShadow = true,
   });
 
-  /// Convenience constructor for Level 0 (pure base)
+  bool get _showBorder => hasBorder ?? border;
+
+  /// Niveau 0 — socle brut.
   const GlassContainer.base({
     super.key,
     required this.child,
@@ -43,13 +62,15 @@ class GlassContainer extends StatelessWidget {
     this.height,
     this.padding = const EdgeInsets.all(16),
     this.margin,
-    this.borderRadius = 16.0,
+    this.borderRadius = 14.0,
     this.borderColor,
     this.border = false,
     this.boxShadow,
+    this.hasBorder,
+    this.showShadow = true,
   }) : level = GlassLevel.level0;
 
-  /// Convenience constructor for Level 1 (standard glass)
+  /// Niveau 1 — plaque standard.
   const GlassContainer.glass({
     super.key,
     required this.child,
@@ -57,13 +78,15 @@ class GlassContainer extends StatelessWidget {
     this.height,
     this.padding = const EdgeInsets.all(16),
     this.margin,
-    this.borderRadius = 16.0,
+    this.borderRadius = 14.0,
     this.borderColor,
     this.border = true,
     this.boxShadow,
+    this.hasBorder,
+    this.showShadow = true,
   }) : level = GlassLevel.level1;
 
-  /// Convenience constructor for Level 2 (floating with inner glow)
+  /// Niveau 2 — bloc flottant (modales, panneaux, overlays).
   const GlassContainer.floating({
     super.key,
     required this.child,
@@ -71,10 +94,12 @@ class GlassContainer extends StatelessWidget {
     this.height,
     this.padding = const EdgeInsets.all(16),
     this.margin,
-    this.borderRadius = 24.0,
+    this.borderRadius = 20.0,
     this.borderColor,
     this.border = true,
     this.boxShadow,
+    this.hasBorder,
+    this.showShadow = true,
   }) : level = GlassLevel.level2;
 
   @override
@@ -98,12 +123,13 @@ class GlassContainer extends StatelessWidget {
       decoration: BoxDecoration(
         color: AppColors.baseLevel0,
         borderRadius: BorderRadius.circular(borderRadius),
-        border: border
+        border: _showBorder
             ? Border.all(
                 color: borderColor ?? Colors.transparent,
                 width: 1,
               )
             : null,
+        boxShadow: showShadow ? boxShadow : null,
       ),
       child: child,
     );
@@ -114,34 +140,29 @@ class GlassContainer extends StatelessWidget {
       width: width,
       height: height,
       margin: margin,
-      child: ClipRRect(
+      padding: padding,
+      decoration: BoxDecoration(
+        color: AppColors.glassLevel1Bg,
         borderRadius: BorderRadius.circular(borderRadius),
-        child: BackdropFilter(
-          filter: ImageFilter.blur(sigmaX: 20, sigmaY: 20),
-          child: Container(
-            padding: padding,
-            decoration: BoxDecoration(
-              borderRadius: BorderRadius.circular(borderRadius),
-              color: AppColors.glassLevel1Bg,
-              border: border
-                  ? Border.all(
-                      color: borderColor ?? AppColors.glassLevel1Border,
-                      width: 1,
-                    )
-                  : null,
-              boxShadow: boxShadow ??
-                  [
-                    BoxShadow(
-                      color: Colors.black.withOpacity(0.2),
-                      blurRadius: 20,
-                      spreadRadius: -5,
-                    ),
-                  ],
-            ),
-            child: child,
-          ),
-        ),
+        border: _showBorder
+            ? Border.all(
+                color: borderColor ?? AppColors.glassLevel1Border,
+                width: 1,
+              )
+            : null,
+        boxShadow: !showShadow
+            ? null
+            : boxShadow ??
+            const [
+              BoxShadow(
+                color: Color(0x59000000), // noir 35 %
+                blurRadius: 18,
+                spreadRadius: -6,
+                offset: Offset(0, 8),
+              ),
+            ],
       ),
+      child: child,
     );
   }
 
@@ -150,54 +171,54 @@ class GlassContainer extends StatelessWidget {
       width: width,
       height: height,
       margin: margin,
-      child: ClipRRect(
-        borderRadius: BorderRadius.circular(borderRadius),
-        child: BackdropFilter(
-          filter: ImageFilter.blur(sigmaX: 40, sigmaY: 40),
-          child: Container(
-            padding: padding,
-            decoration: BoxDecoration(
-              borderRadius: BorderRadius.circular(borderRadius),
-              color: AppColors.glassLevel2Bg,
-              border: border
-                  ? Border(
-                      top: BorderSide(
-                        color: borderColor ?? AppColors.glassLevel2InnerGlow,
-                        width: 1,
-                      ),
-                      left: BorderSide(
-                        color: borderColor ?? AppColors.glassLevel2InnerGlow,
-                        width: 1,
-                      ),
-                      right: BorderSide(
-                        color: borderColor ?? AppColors.glassLevel2Border,
-                        width: 1,
-                      ),
-                      bottom: BorderSide(
-                        color: borderColor ?? AppColors.glassLevel2Border,
-                        width: 1,
-                      ),
-                    )
-                  : null,
-              boxShadow: boxShadow ??
-                  [
-                    BoxShadow(
-                      color: Colors.black.withOpacity(0.5),
-                      blurRadius: 30,
-                      spreadRadius: -10,
-                      offset: const Offset(0, 10),
-                    ),
-                    BoxShadow(
-                      color: AppColors.primary.withOpacity(0.1),
-                      blurRadius: 40,
-                      spreadRadius: -10,
-                    ),
-                  ],
-            ),
-            child: child,
-          ),
+      padding: padding,
+      decoration: BoxDecoration(
+        // Dégradé très court : arête haute captant la « lumière du projecteur ».
+        gradient: const LinearGradient(
+          colors: [Color(0xFF262019), Color(0xFF1F1815)],
+          stops: [0.0, 0.45],
+          begin: Alignment.topCenter,
+          end: Alignment.bottomCenter,
         ),
+        borderRadius: BorderRadius.circular(borderRadius),
+        border: _showBorder
+            ? Border(
+                top: BorderSide(
+                  color: borderColor ?? AppColors.glassLevel2InnerGlow,
+                  width: 1,
+                ),
+                left: BorderSide(
+                  color: borderColor ?? AppColors.glassLevel2Border,
+                  width: 1,
+                ),
+                right: BorderSide(
+                  color: borderColor ?? AppColors.glassLevel2Border,
+                  width: 1,
+                ),
+                bottom: BorderSide(
+                  color: borderColor ?? AppColors.glassLevel2Border,
+                  width: 1,
+                ),
+              )
+            : null,
+        boxShadow: !showShadow
+            ? null
+            : boxShadow ??
+            const [
+              BoxShadow(
+                color: Color(0xA6000000), // noir 65 %
+                blurRadius: 40,
+                spreadRadius: -12,
+                offset: Offset(0, 20),
+              ),
+              BoxShadow(
+                color: Color(0x1FD9541F), // halo ember 12 %
+                blurRadius: 48,
+                spreadRadius: -18,
+              ),
+            ],
       ),
+      child: child,
     );
   }
 }