fix: resolve all compile errors from Stitch theme merge

- Add missing AppTheme animation constants (durationSm/Md/Lg/Xl, curveSmooth)
  to satisfy remote widget references.
- Replace deprecated GlassContainer(opacity:) with .glass()/.floating()/.base()
  in login_screen, live_tv_tab, mobile_live_tv_tab, player_screen,
  dashboard_screen.
- Fix const-eval errors by removing const from BorderSide/Text/BoxDecoration
  using AppColors.focusColor and AppColors.border (runtime getters).
- Fix subtitle_service.dart: padEnd → padRight (Dart String API).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

lib/mobile/features/iptv/widgets/mobile_live_tv_tab.dart

@@ -144,9 +144,8 @@ class _MobileLiveTVTabState extends ConsumerState<MobileLiveTVTab> {
                 // Header & Search
                 Padding(
                   padding: const EdgeInsets.all(16),
-                  child: GlassContainer(
+                  child: GlassContainer.glass(
                     borderRadius: 16,
-                    opacity: 0.1,
                     padding:
                         const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                     child: Row(
@@ -352,9 +351,8 @@ class _MobileChannelTile extends StatelessWidget {
             ? '/api/xtream/${channel.streamIcon}'
             : null;
 
-    return GlassContainer(
+    return GlassContainer.glass(
       borderRadius: 12,
-      opacity: 0.15,
       padding: EdgeInsets.zero,
       child: InkWell(
         onTap: onTap,