Allow a personal token for package upload

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XqsmB8BBnudp4djsjWpk11

.gitea/workflows/convert.yaml

@@ -49,7 +49,7 @@ jobs:
 
       - name: upload to generic package registry
         env:
-          TOKEN: ${{ secrets.GITEA_TOKEN }}
+          TOKEN: ${{ secrets.PACKAGES_TOKEN || secrets.GITEA_TOKEN }}
           PACKAGE_URL: ${{ gitea.server_url }}/api/packages/${{ gitea.repository_owner }}/generic/addresses/v1.1.1
         run: |
           set -eu