Initial commit: AudiOhm - Alternative Spotify avec streaming YouTube

Backend:
- FastAPI avec PostgreSQL et Redis
- Authentification JWT complète
- API REST pour musique, playlists, recherche
- Streaming audio via yt-dlp
- SQLAlchemy 2.0 async

Frontend:
- Flutter avec thème néon cyberpunk
- State management Riverpod
- Layout adaptatif desktop/mobile
- Lecteur audio avec mini-player

Infrastructure:
- Docker Compose (PostgreSQL + Redis)
- Scripts d'installation automatisés
- Scripts de build pour exécutables

Fichiers ajoutés:
- BUILD_CLIENT_*.bat/sh: Scripts de compilation
- BUILD_CLIENT_README.md: Documentation compilation
- CHECK_FLUTTER.sh: Vérificateur d'environnement
- requirements.txt mis à jour pour Python 3.13
- Modèles SQLAlchemy corrigés (metadata -> extra_metadata)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

CHECK_FLUTTER.sh

@@ -0,0 +1,81 @@
+#!/bin/bash
+# ============================================================================
+# Flutter Build Environment Checker
+# ============================================================================
+
+echo "========================================"
+echo "  FLUTTER BUILD CHECKER"
+echo "========================================"
+echo ""
+
+# Check Flutter installation
+if ! command -v flutter &> /dev/null; then
+    echo "[ERROR] Flutter is NOT installed!"
+    echo ""
+    echo "To install Flutter:"
+    echo "  Linux: https://docs.flutter.dev/get-started/install/linux"
+    echo "  Windows: https://docs.flutter.dev/get-started/install/windows"
+    echo "  macOS: https://docs.flutter.dev/get-started/install/macos"
+    exit 1
+fi
+
+echo "[✓] Flutter is installed"
+echo ""
+
+# Show Flutter version
+echo "Flutter version:"
+flutter --version
+echo ""
+
+# Check Flutter doctor
+echo "Flutter doctor status:"
+flutter doctor
+echo ""
+
+# Check if we can build for current platform
+OS="$(uname -s)"
+case "$OS" in
+  Linux*)
+    echo "Checking Linux build capability..."
+    flutter build linux --help > /dev/null 2>&1
+    if [ $? -eq 0 ]; then
+        echo "[✓] Linux build is supported"
+        echo ""
+        echo "To build the Windows client:"
+        echo "  ./BUILD_CLIENT_LINUX.sh"
+    else
+        echo "[!] Linux build is NOT available"
+        echo "Install dependencies:"
+        echo "  sudo apt install clang cmake ninja-build pkg-config libgtk-3-dev"
+    fi
+    ;;
+  Darwin*)
+    echo "Checking macOS build capability..."
+    flutter build macos --help > /dev/null 2>&1
+    if [ $? -eq 0 ]; then
+        echo "[✓] macOS build is supported"
+    else
+        echo "[!] macOS build is NOT available (install Xcode)"
+    fi
+    ;;
+  MINGW*|MSYS*|CYGWIN*)
+    echo "Windows detected via Git Bash/MSYS"
+    flutter build windows --help > /dev/null 2>&1
+    if [ $? -eq 0 ]; then
+        echo "[✓] Windows build is supported"
+        echo ""
+        echo "To build the Windows client:"
+        echo "  BUILD_CLIENT_WINDOWS.bat"
+    else
+        echo "[!] Windows build is NOT available (install Visual Studio)"
+    fi
+    ;;
+  *)
+    echo "Unknown OS: $OS"
+    ;;
+esac
+
+echo ""
+echo "========================================"
+echo "  CHECK COMPLETE"
+echo "========================================"