Remove Lavaplayer and migrate to Lavalink

Replaced the bot's audio handling system by removing Lavaplayer dependencies and migrating to a Lavalink v4 node. Updated `MusicManager`, `TrackScheduler`, and related classes to utilize the `LavalinkClient`. Refactored playlist and track loading logic, task integrations, and event dispatch to integrate with the remote node. Deprecated the custom Udio source, preserving references for a future plugin port. Documented configuration and deployment details for the new audio architecture.

bot.properties.example

@@ -20,6 +20,10 @@ NETNEUTRALITY_VISITOR_DATA=
 NETNEUTRALITY_CIPHER_URL=http://localhost:8001
 NETNEUTRALITY_CIPHER_PASSWORD=
 
+NETNEUTRALITY_LAVALINK_URI=ws://lavalink:2333
+NETNEUTRALITY_LAVALINK_PASSWORD=youshallnotpass
+NETNEUTRALITY_LAVALINK_NAME=main
+
 NETNEUTRALITY_SENTRY_DSN=
 GITLAB_HOST=
 GITLAB_TOKEN=