Fix Docker Hub description update: use --rawfile and capture error response

.gitea/workflows/docker-publish.yml

@@ -100,16 +100,18 @@ jobs:
             exit 1
           fi
           HTTP_CODE=$(jq -n \
-            --arg full "$(cat DOCKER_HUB.md)" \
+            --rawfile full DOCKER_HUB.md \
             --arg short "Portable AI dev environment for opencode. Debian-based with git, Node.js, AWS CLI, and SSH support. Available in base and omos (multi-agent) variants." \
             '{"full_description": $full, "description": $short}' | \
-            curl -s -o /dev/null -w "%{http_code}" -X PATCH \
+            curl -s -o /tmp/hub-response.txt -w "%{http_code}" -X PATCH \
               "https://hub.docker.com/v2/repositories/${{ vars.DOCKERHUB_USERNAME }}/opencode-devbox/" \
               -H "Authorization: JWT $TOKEN" \
               -H "Content-Type: application/json" \
               -d @-)
           echo "Docker Hub API returned: $HTTP_CODE"
           if [ "$HTTP_CODE" != "200" ]; then
+            echo "Response body:"
+            cat /tmp/hub-response.txt
             echo "::error::Docker Hub description update failed with HTTP $HTTP_CODE"
             exit 1
           fi