Update youtube-source to 2be8e542 snapshot

[nextinfinity]

Summary

• Update youtube-source from 1.18.2 to the requested commit: 2be8e542d3f6f178e048dca565892684c2e40177-SNAPSHOT.
• Add the Lavalink snapshots repository, restricted to snapshot artifacts in dev.lavalink.youtube.
• No application code, auth settings, diagnostics, or testing infrastructure changes.

This commit includes the upstream TV PlayStation 4 User-Agent fix for "The page needs to be reloaded", plus the cipher-response lifetime fix that avoids connection starvation. It is an unreleased snapshot, not a stable release or a guarantee of playback success.

Validation

• JDK 25: ./gradlew --no-daemon clean shadowJar passes with no API changes required.
• dependencyInsight confirms both v2 and common resolve to the requested commit snapshot (timestamped build 20260917.205250-1).
• Temporary local smoke checks pass for default client order, blank settings, cipher + poToken configuration, and incomplete token-pair rejection; no test infrastructure committed.
• Git whitespace check passes.
• Live OAuth/video playback remains to be verified on the deployment host. Retry x8jAY2CoOBg using the existing OAuth token after deploying.

Deploy / rollback

The standard Compose file uses :latest; publish a release after merge, then docker compose pull && docker compose up -d. Keep the previous release image tag available for rollback if this snapshot regresses playback.