chore: Add release workflow for automated builds and publishing

.github/workflows/on-release.yaml

@@ -0,0 +1,72 @@
+# Release builds and publish a new release.
+# It will run necessary tests. Then it builds the docker image, pushes it to the container registry, and creates a new Github Release (and git tag) with automated release notes (automated release notes powered by GitHub).
+
+name: Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      nextVersion:
+        description: 'specify the release version in the semver format v[major].[minor].[patch] e.g. v0.0.0'
+        required: true
+
+# base permissions for all jobs should be minimal
+permissions:
+  contents: read
+
+env:
+  REGISTRY: ghcr.io/openmcp-project
+  IMAGE_NAME: mcp-ui-frontend
+
+jobs:
+  run-build:
+    uses: ./.github/workflows/build.yaml
+
+  release:
+    runs-on: ubuntu-latest
+    needs: 
+      - run-build
+
+    permissions:
+      contents: write # write release tag to the repo
+      packages: write # push the container to ghcr
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          fetch-depth: 0  # Fetch all history for all tags and branches
+
+      - name: Check if tag already exists
+        id: check_tag
+        run: |
+          if git rev-parse ${{ github.event.inputs.nextVersion }} >/dev/null 2>&1
+          then
+            echo "Tag ${{ github.event.inputs.nextVersion }} already exists."
+            exit 1
+          else
+            echo "Tag does not exit. Building release version ${{ github.event.inputs.nextVersion }}"
+          fi
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@74a5d142397b4f367a81961eba4e8cd7edddf772 # v3.4.0
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push Docker image
+        id: push
+        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6.15.0
+        with:
+          context: .
+          push: true
+          tags:  ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.event.inputs.nextVersion }}
+
+      - name: Create Release with autogenerated release notes
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release create ${{ github.event.inputs.nextVersion }} \
+            --generate-notes \
+            --target ${{ github.sha }}