feat(design): Projector Noir theme - tungsten amber on film-black

Full visual refonte replacing the generic neon-blue glass look:

- palette: warm film-black surface ladder, tungsten amber primary,
  warm taupe secondary, verdigris teal tertiary; semantic and
  category colors retuned to match (coral live, gold movies)
- typography: Syne (display/headlines) + Instrument Sans (body/UI)
  replace Space Grotesk/Inter/Outfit across all screens
- glassmorphism tokens warmed (amber inner glow, warm-white borders)
- web player theme.css + index.html loader mirror the new tokens
- hardcoded Colors.blue* in streaming settings and recordings tabs
  now use AppColors tokens
- DESIGN_SYSTEM.md updated to v3.0 Projector Noir

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

lib/mobile/widgets/mobile_scaffold.dart

@@ -1,4 +1,4 @@
-import 'package:flutter/material.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:google_fonts/google_fonts.dart';
 import '../../core/theme/app_colors.dart';
@@ -60,9 +60,9 @@ class MobileScaffold extends ConsumerWidget {
           selectedItemColor: AppColors.primary,
           unselectedItemColor: AppColors.textSecondary,
           selectedLabelStyle:
-              GoogleFonts.inter(fontWeight: FontWeight.w600, fontSize: 11),
+              GoogleFonts.instrumentSans(fontWeight: FontWeight.w600, fontSize: 11),
           unselectedLabelStyle:
-              GoogleFonts.inter(fontWeight: FontWeight.w500, fontSize: 11),
+              GoogleFonts.instrumentSans(fontWeight: FontWeight.w500, fontSize: 11),
           items: const [
             BottomNavigationBarItem(
               icon: Icon(Icons.live_tv_rounded),