ci: add pre-verification with registry login test

Unified pattern enforced:
- test job: runs on all branches + PRs
- build-push job: only on main push, depends on test
- Proper env vars (GOPRIVATE, REGISTRY, IMAGE)
- Install Node.js before checkout
- Install docker only in build-push
- Docker login + build + push + prune

---------

Co-authored-by: Test <[email protected]>
Reviewed-on: #5

.gitea/workflows/ci.yaml

@@ -41,14 +41,55 @@ jobs:
     runs-on: golang
     steps:
       - name: Install Node.js and Docker
-        run: apt-get update && apt-get install -y nodejs docker.io
+        run: |
+          apt-get update
+          apt-get install -y nodejs docker.io
 
       - name: Checkout code
         uses: actions/checkout@v4
 
       - name: Get short SHA
         id: sha
-        run: echo "short_sha=$(git rev-parse --short HEAD)" >> $GITHUB_OUTPUT
+        run: |
+          SHORT_SHA=$(git rev-parse --short HEAD)
+          echo "short_sha=${SHORT_SHA}" >> $GITHUB_OUTPUT
+
+      - name: Pre-verify Docker, Registry, and Credentials
+        run: |
+          echo "=== Docker Daemon Check ==="
+          if ! docker version &>/dev/null; then
+            echo "❌ FAILED: Docker daemon not accessible"
+            exit 1
+          fi
+          echo "✓ Docker daemon is running"
+          docker version --format "Engine: {{.Server.Version}}"
+          echo ""
+          echo "=== Registry Credentials Check ==="
+          if [ -z "${REGISTRY_USER}" ] || [ -z "${REGISTRY_TOKEN}" ]; then
+            echo "❌ FAILED: FORGEJO_REGISTRY_USER or FORGEJO_REGISTRY_TOKEN not set"
+            exit 1
+          fi
+          echo "✓ Registry credentials are set"
+          echo ""
+          echo "=== Registry Login Test ==="
+          if ! echo "${REGISTRY_TOKEN}" | docker login "${REGISTRY}" --username "${REGISTRY_USER}" --password-stdin &>/dev/null; then
+            echo "❌ FAILED: Registry login failed - credentials may be invalid"
+            exit 1
+          fi
+          echo "✓ Registry login successful"
+          docker logout "${REGISTRY}" &>/dev/null || true
+          echo ""
+          echo "=== Dockerfile Check ==="
+          if [ ! -f Dockerfile ]; then
+            echo "❌ FAILED: Dockerfile not found"
+            exit 1
+          fi
+          echo "✓ Dockerfile exists"
+          echo ""
+          echo "=== All pre-checks passed ==="
+        env:
+          REGISTRY_USER: ${{ secrets.FORGEJO_REGISTRY_USER }}
+          REGISTRY_TOKEN: ${{ secrets.FORGEJO_REGISTRY_TOKEN }}
 
       - name: Registry login
         run: |
@@ -58,7 +99,7 @@ jobs:
           REGISTRY_USER: ${{ secrets.FORGEJO_REGISTRY_USER }}
           REGISTRY_TOKEN: ${{ secrets.FORGEJO_REGISTRY_TOKEN }}
 
-      - name: Build and push image
+      - name: Build Docker image
         run: |
           docker build --no-cache \
             -t "${IMAGE}:${{ steps.sha.outputs.short_sha }}" \