Gitea copy: $uicide Music Bot — image, Unraid template, CI, publishing

Fork of purnell569/MusicBot 0.7.1 (JMusicBot), kept here as a reliable
copy with a container image built and served from this Gitea.

- README retitled "$uicide Music Bot"; lineage table, Gitea image, Unraid
  and release instructions. Nothing under src/ changes.
- Dockerfile: Maven stage on $BUILDPLATFORM (JAR is arch-neutral, so no
  QEMU for the build), OCI labels point at this repo and record commit and
  version via GIT_SHA/VERSION build args.
- docker/entrypoint.sh: check the data dir is writable up front (the bot's
  own error for that is a misleading "another instance is running"), and
  on a missing config.txt run the bot's generate-config and stop with
  instructions instead of prompting on a console that does not exist.
- deploy/unraid/musicbot.xml: Unraid template, --user 99:100 default.
- .gitea/workflows/build-and-test.yml: mvn verify + docker build on push;
  its presence makes Gitea ignore the GitHub-only workflows in .github/.
- scripts/build-and-publish-unraid.sh + docs/PUBLISHING.md: release
  runbook (keychain-safe registry push, release with zipped JAR).
- docker-compose.example.yml points at the Gitea image.

Upstream's v0.7.1 tag is preserved as upstream/v0.7.1; this repository's
own release tag v0.7.1 is on this commit.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

docker-compose.example.yml

@@ -1,8 +1,6 @@
-version: '3.8'
-
 services:
   jmusicbot:
-    image: ghcr.io/purnell569/musicbot:latest # or ghcr.io/purnell569/musicbot:0.7.1 for a specific version
+    image: gitea.milesward.dev/mward4/musicbot:latest # or gitea.milesward.dev/mward4/musicbot:0.7.1 to pin a release
     container_name: jmusicbot
     # The container runs as non-root user 'jmusicbot' (UID 10001) for security.
     # Ensure the mounted volume directory is readable/writable by UID 10001,