chore: add CI, dependabot, and release workflow

.github/workflows/release.yml

@@ -0,0 +1,25 @@
+# rolling :latest image, published manually from the Actions tab (Run workflow)
+name: release
+on:
+  workflow_dispatch:
+permissions:
+  contents: read
+  packages: write
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: docker/setup-buildx-action@v3
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: |
+            ghcr.io/parkan/go-hauk:latest
+            ghcr.io/parkan/go-hauk:${{ github.sha }}