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>

backend/.env.example

@@ -0,0 +1,114 @@
+# =============================================================================
+# Spotify Le 2 - Environment Variables
+# =============================================================================
+# Copy this file to .env and fill in your values.
+# DO NOT commit .env to version control.
+
+# -----------------------------------------------------------------------------
+# Application
+# -----------------------------------------------------------------------------
+APP_NAME="Spotify Le 2"
+APP_VERSION="0.1.0"
+DEBUG=true
+API_V1_PREFIX="/api/v1"
+
+# Server
+HOST=0.0.0.0
+PORT=8000
+
+# CORS - Comma-separated list of allowed origins
+BACKEND_CORS_ORIGINS=http://localhost:3000,http://localhost:8000
+
+# -----------------------------------------------------------------------------
+# Database (PostgreSQL)
+# -----------------------------------------------------------------------------
+POSTGRES_HOST=localhost
+POSTGRES_PORT=5432
+POSTGRES_USER=spotify
+POSTGRES_PASSWORD=change_this_password_in_production
+POSTGRES_DB=spotify_le_2
+
+# -----------------------------------------------------------------------------
+# Redis
+# -----------------------------------------------------------------------------
+REDIS_HOST=localhost
+REDIS_PORT=6379
+REDIS_PASSWORD=
+REDIS_DB=0
+# Alternative: Full Redis URL (overrides above if set)
+# REDIS_URL=redis://:password@localhost:6379/0
+
+# -----------------------------------------------------------------------------
+# JWT Security
+# -----------------------------------------------------------------------------
+# IMPORTANT: Change this to a strong random string in production!
+SECRET_KEY=change-this-secret-key-in-production-use-openssl-rand-hex-32
+ALGORITHM=HS256
+ACCESS_TOKEN_EXPIRE_MINUTES=15
+REFRESH_TOKEN_EXPIRE_DAYS=7
+
+# Password hashing
+PASSWORD_HASH_ALGORITHM=bcrypt
+PASSWORD_HASH_ROUNDS=12
+
+# -----------------------------------------------------------------------------
+# Storage
+# -----------------------------------------------------------------------------
+STORAGE_PATH=./storage
+AUDIO_CACHE_PATH=./storage/audio/cache
+AUDIO_PERMANENT_PATH=./storage/audio/permanent
+THUMBNAILS_PATH=./storage/thumbnails
+MAX_CACHE_SIZE_GB=50
+
+# -----------------------------------------------------------------------------
+# YouTube
+# -----------------------------------------------------------------------------
+# Get your API key from: https://console.cloud.google.com/
+YOUTUBE_API_KEY=
+YTDLP_PATH=yt-dlp
+
+# -----------------------------------------------------------------------------
+# Spotify (for playlist import)
+# -----------------------------------------------------------------------------
+# Get your credentials from: https://developer.spotify.com/dashboard
+SPOTIFY_CLIENT_ID=
+SPOTIFY_CLIENT_SECRET=
+SPOTIFY_REDIRECT_URI=http://localhost:8000/api/v1/import/spotify/callback
+
+# -----------------------------------------------------------------------------
+# Last.fm (for metadata and recommendations)
+# -----------------------------------------------------------------------------
+# Get your API key from: https://www.last.fm/api/account/create
+LASTFM_API_KEY=
+LASTFM_SECRET=
+
+# -----------------------------------------------------------------------------
+# Rate Limiting
+# -----------------------------------------------------------------------------
+RATE_LIMIT_PER_MINUTE=100
+RATE_LIMIT_BURST=200
+
+# -----------------------------------------------------------------------------
+# File Upload
+# -----------------------------------------------------------------------------
+MAX_FILE_SIZE_MB=100
+ALLOWED_AUDIO_TYPES=audio/mpeg,audio/ogg,audio/wav,audio/flac
+
+# -----------------------------------------------------------------------------
+# Audio Processing
+# -----------------------------------------------------------------------------
+FFMPEG_PATH=ffmpeg
+AUDIO_QUALITY=high
+BITRATE=320
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+LOG_LEVEL=INFO
+LOG_FILE_PATH=./logs
+
+# -----------------------------------------------------------------------------
+# Pagination
+# -----------------------------------------------------------------------------
+DEFAULT_PAGE_SIZE=20
+MAX_PAGE_SIZE=100