Add Gitea release workflow; pull image from registry by default

CI builds and pushes the comfyui-nvidia image to the Gitea container
registry on every v* tag, mirroring the figment release workflow. Compose
now references the registry image (with build context kept for local
iteration) and the docs reflect the pull-by-default flow.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -0,0 +1,50 @@
+name: release
+
+# Tag a commit as v* (e.g. v0.1.0) to build and publish the comfyui-nvidia
+# image to the Gitea container registry. The deployed compose file
+# references this image, so a successful release is what makes a new build
+# reachable to deployers.
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  build-docker:
+    name: Build & Push Docker Image
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/catthehacker/ubuntu:act-latest
+    env:
+      REGISTRY: git.anomalous.dev
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Extract version
+        id: version
+        run: echo "version=${GITHUB_REF_NAME#v}" >> "$GITHUB_OUTPUT"
+
+      - name: Compute image name
+        id: meta
+        run: |
+          owner=$(echo "${{ github.repository_owner }}" | tr '[:upper:]' '[:lower:]')
+          echo "image=${{ env.REGISTRY }}/${owner}/comfyui-nvidia" >> "$GITHUB_OUTPUT"
+
+      - name: Log in to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.TOKEN_GITEA }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: Dockerfile
+          push: true
+          tags: |
+            ${{ steps.meta.outputs.image }}:${{ steps.version.outputs.version }}
+            ${{ steps.meta.outputs.image }}:latest