docs: consolidate documentation into organized structure

- Move 12 markdown files from root to docs/ subdirectories
- Organize documentation by category:
  • docs/troubleshooting/ (1 file)  - Technical troubleshooting guides
  • docs/deployment/      (4 files) - Deployment and security documentation
  • docs/guides/          (3 files) - Feature-specific guides
  • docs/planning/        (4 files) - Planning and improvement proposals

Root directory cleanup:
- Reduced from 16 to 4 markdown files in root
- Only essential project files remain:
  • CLAUDE.md (AI instructions)
  • README.md (Main project readme)
  • CLEANUP_PLAN.md (Current cleanup plan)
  • SRC_STRUCTURE_IMPROVEMENTS.md (Structure improvements)

This improves:
✅ Documentation discoverability
✅ Logical organization by purpose
✅ Clean root directory
✅ Better maintainability

.env.example

@@ -41,4 +41,28 @@ RATE_LIMIT_WINDOW=60
 RATE_LIMIT_AUTH=10
 RATE_LIMIT_AUTH_WINDOW=300
 RATE_LIMIT_API=30
-RATE_LIMIT_API_WINDOW=60
+RATE_LIMIT_API_WINDOW=60
+
+# OAuth Provider Konfiguration
+APP_URL=https://localhost
+
+# Spotify OAuth
+SPOTIFY_CLIENT_ID=your_spotify_client_id
+SPOTIFY_CLIENT_SECRET=your_spotify_client_secret
+SPOTIFY_REDIRECT_URI=https://localhost/oauth/spotify/callback
+
+# Apple Music OAuth
+APPLE_MUSIC_CLIENT_ID=your_apple_music_client_id
+APPLE_MUSIC_TEAM_ID=your_apple_music_team_id
+APPLE_MUSIC_KEY_ID=your_apple_music_key_id
+APPLE_MUSIC_PRIVATE_KEY=your_apple_music_private_key_path_or_content
+APPLE_MUSIC_REDIRECT_URI=https://localhost/oauth/apple-music/callback
+
+# Tidal OAuth
+TIDAL_CLIENT_ID=your_tidal_client_id
+TIDAL_CLIENT_SECRET=your_tidal_client_secret
+TIDAL_REDIRECT_URI=https://localhost/oauth/tidal/callback
+
+# Vault Configuration
+# Generate with: php console.php vault:generate-key
+# VAULT_ENCRYPTION_KEY=base64_encoded_key_here