CI: authenticated checkout for private repo; server CLAUDE.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -16,7 +16,8 @@ jobs:
         run: |
           apt-get update -qq && apt-get install -y -qq git unzip curl > /dev/null
           git init .
-          git fetch --depth 1 https://git.rehbock.xyz/${{ github.repository }}.git ${{ github.sha }}
+          # Token auth: the repo is private (until it's deliberately open-sourced).
+          git fetch --depth 1 https://gitea-actions:${{ secrets.GITHUB_TOKEN }}@git.rehbock.xyz/${{ github.repository }}.git ${{ github.sha }}
           git checkout FETCH_HEAD
 
       - name: Install Node.js