docs: document 502 error fix for Docker registry and update workflow

Added a detailed session log documenting the root cause and resolution of 502 errors during Docker image pushes. Updated `.gitea/workflows/docker-publish.yaml` to bypass Pangolin for internal registry access and disable attestation manifests to prevent additional token requests.

.gitea/workflows/docker-publish.yaml

@@ -95,6 +95,12 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      # Pangolin-Bypass: Gitea direkt intern erreichbar machen (10.0.0.22:3000)
+      # Hintergrund: Ohne diesen Eintrag routet der Runner über Pangolin (git.mo-code.at),
+      # was bei großen Docker-Layern (70+ Sekunden Upload) mit 502 abbricht.
+      - name: Registry intern auflösen (Pangolin-Bypass)
+        run: echo "10.0.0.22 git.mo-code.at" | sudo tee -a /etc/hosts
+
       - name: Log in to the Container registry
         uses: docker/login-action@v3
         with:
@@ -121,6 +127,10 @@ jobs:
           platforms: linux/arm64
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          # Attestation-Manifeste deaktivieren: verhindert extra OAuth-Token-Requests
+          # die bei proxied Registries (Pangolin) ebenfalls mit 502 fehlschlagen können
+          provenance: false
+          sbom: false
           build-args: |
             DOCKER_BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')
             VERSION=${{ github.sha }}