v2.3: Major refactoring, Lavalink music system, Spotify support, CI/CD

- Full refactoring: max 200 lines/file, max 3 files/dir, KISS/DRY/SOLID
- Lavalink client 3.4.0 + LavaSrc plugin (Spotify, Apple Music, Deezer)
- 3-bot architecture: main (!), music (q!), radio (r!)
- Filters: bassboost, nightcore, vaporwave, equalizer
- Slash commands for music (/play, /skip, etc.)
- Persistent queue in SQLite, auto-leave timer
- Radio manager with auto-reconnect
- Custom welcome GIF greetings via nekos.life
- JDA 5.6.1, gson 2.14, hikaricp 6.3, all deps updated
- Fixed YouTube playback via ytmsearch (LavaSrc)
- CI/CD: Docker publish + release workflows
- SpotBugs: all real bugs fixed, ignoreFailures=false
- Checkstyle: Google Style (adapted), 0 violations

.env.example

@@ -1,6 +1,20 @@
+# Main bot token (all features)
 DISCORD_BOT_TOKEN=your_token_here
+# Music bot token (only music via Lavalink) - OPTIONAL
+DISCORD_BOT_TOKEN_MUSIC=your_music_token
+# Radio bot token (only radio) - OPTIONAL
+DISCORD_BOT_TOKEN_RADIO=your_radio_token
 BOT_PREFIX=!
 BOT_ACTIVITY=Используй !help
 HEALTH_HTTP_PORT=8712
 SUPER_ADMIN_ID=your_discord_user_id
 DB_PATH=data/bot.db
+
+# Lavalink
+LAVALINK_HOST=127.0.0.1
+LAVALINK_PORT=2333
+LAVALINK_PASSWORD=youshallnotpass
+
+# Spotify API (для LavaSrc)
+SPOTIFY_CLIENT_ID=your_spotify_client_id
+SPOTIFY_CLIENT_SECRET=your_spotify_client_secret