feat: Modernisation UI/UX et configuration Flutter multi-plateforme

Phase 1 - Corrections Critiques:
- Fixed memory leaks dans music_provider.dart (stream subscriptions)
- Fixed race conditions dans search_provider.dart (stale results)
- Fixed token refresh errors dans api_service.dart
- Improved error handling avec messages utilisateur
- Changed API URL to HTTPS by default

Phase 2 - Améliorations UX Desktop:
- Ajouté cursor pointers sur tous les éléments cliquables
- Implémenté hover states avec effets néon glow (200ms transitions)
- Créé skeleton loading states avec shimmer animation
- Ajouté widgets: ClickableWrapper, ErrorDisplay, SkeletonLoading
- Enhanced visual feedback pour desktop users

Phase 3 - Configuration Flutter:
- Configuré Android (Gradle 8.1.0, Kotlin 1.9.0, minSdk 21, targetSdk 34)
- Créé launcher icons cyberpunk néon (5 densités)
- Configuré Windows desktop (structure complète)
- Activé Linux desktop support
- Ajouté package équatable pour entités de domaine
- Corrigé imports (colors.dart, auth_provider.dart)
- Fixed Dio API compatibility (RequestOptions)

Documentation:
- STYLE_GUIDE.md: Guide complet (100+ pages)
- DESIGN_IMPLEMENTATION_GUIDE.md: Implémentation Flutter
- BUILD_STATUS.md: Status builds + troubleshooting
- QUICKSTART_BUILDS.md: Guide rapide
- BUILD_INDEX.md: Index documentation
- PHASE_1_CORRECTIONS.md: Corrections Phase 1
- PHASE_2_UX_IMPROVEMENTS.md: Améliorations Phase 2
- PR_REVIEW_SUMMARY.md: Revue code complète
- CODE_ANALYSIS_AND_PRIORITIES.md: Analyse code

Scripts & Builds:
- BUILD_ALL.sh: Script automatisé builds multi-plateforme
- builds/: Structure avec README par plateforme
- design-system/: Système de design complet

Backend:
- Ajouté streaming HTTP Range pour audio progressif
- Enhanced YouTube service avec métadonnées complètes
- Improved error handling et validation

Generated with [Claude Code](https://claude.com/claude-code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

frontend/linux/runner/CMakeLists.txt

@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.10)
+project(runner LANGUAGES CXX)
+
+# Define the application target. To change its name, change BINARY_NAME in the
+# top-level CMakeLists.txt, not the value here, or `flutter run` will no longer
+# work.
+#
+# Any new source files that you add to the application should be added here.
+add_executable(${BINARY_NAME}
+  # "flutter/flutter_window.cc"
+  # "flutter/flutter_window.h"
+  # "flutter/engine_connection.cc"
+  # "flutter/engine_connection.h"
+  # "flutter/process_launcher.cc"
+  # "flutter/process_launcher.h"
+  "main.cpp"
+  "my_flutter_app.cc"
+  "my_flutter_app.h"
+)
+
+# Apply the standard set of build settings. This can be removed for applications
+# that need different build settings.
+apply_standard_settings(${BINARY_NAME})
+
+# Add preprocessor definitions for the build version.
+target_compile_definitions(${BINARY_NAME} PRIVATE
+  "FLUTTER_VERSION=\"${FLUTTER_VERSION}\""
+  "FLUTTER_VERSION_MAJOR=${FLUTTER_VERSION_MAJOR}"
+  "FLUTTER_VERSION_MINOR=${FLUTTER_VERSION_MINOR}"
+  "FLUTTER_VERSION_PATCH=${FLUTTER_VERSION_PATCH}"
+  "FLUTTER_VERSION_BUILD=${FLUTTER_VERSION_BUILD}"
+)
+
+# Disable Linux macros in Flutter headers.
+target_compile_definitions(${BINARY_NAME} PRIVATE "_GNU_SOURCE=1")
+
+# Add dependency libraries and include directories. Add any application-specific
+# dependencies here.
+target_link_libraries(${BINARY_NAME} PRIVATE flutter flutter_wrapper_app)
+target_include_directories(${BINARY_NAME} PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}")
+
+# Run the Flutter tool portions of the build. This must not be removed.
+add_dependencies(${BINARY_NAME} flutter_assemble)