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.

.env.example

@@ -1,5 +1,4 @@
 NETNEUTRALITY_TAG=latest
-
 NETNEUTRALITY_BOT_ENV=dev
 NETNEUTRALITY_BOT_TOKEN=
 NETNEUTRALITY_BOT_PREFIX=$
@@ -12,13 +11,17 @@ MYSQL_PORT=3306
 MYSQL_USER=java
 MYSQL_PASSWORD=password
 MYSQL_DATABASE=netneutrality
-MYSQL_ROOT_PASSWORD=password
-MARIADB_AUTO_UPGRADE=1
 
+NETNEUTRALITY_LAVALINK_URI=ws://lavalink:2333
+NETNEUTRALITY_LAVALINK_PASSWORD=youshallnotpass
+NETNEUTRALITY_LAVALINK_NAME=dev-player
 NETNEUTRALITY_PO_TOKEN=
 NETNEUTRALITY_VISITOR_DATA=
-NETNEUTRALITY_CIPHER_URL=http://localhost:8001
+NETNEUTRALITY_OAUTH_TOKEN=
+NETNEUTRALITY_CIPHER_URL=http://ejs-api:8001
 NETNEUTRALITY_CIPHER_PASSWORD=
+NETNEUTRALITY_WEBPO_URL=http://webpo:8080
+NETNEUTRALITY_WEBPO_PASSWORD=
 
 NETNEUTRALITY_SENTRY_DSN=
 GITLAB_HOST=