Use REGISTRY_TOKEN (scoped write:package) for registry publish

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.forgejo/workflows/package.yml

@@ -14,7 +14,7 @@ jobs:
       # actions require. Everything runs as shell steps and clones manually.
       - name: Build and publish
         env:
-          PUBLISH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PUBLISH_TOKEN: ${{ secrets.REGISTRY_TOKEN }}
         run: |
           set -euo pipefail
           VERSION="${GITHUB_REF_NAME#v}"