Automate version tags with workflow dispatch

.github/workflows/release.yml

@@ -0,0 +1,48 @@
+name: Release
+
+on:
+  workflow_dispatch:
+    inputs:
+      bump:
+        description: "Version bump"
+        type: choice
+        options: [patch, minor, major]
+        default: patch
+
+permissions:
+  contents: write
+
+jobs:
+  tag-and-release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Ensure release runs from main
+        if: github.ref != 'refs/heads/main'
+        run: |
+          echo "Releases must be cut from the main branch."
+          exit 1
+
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # need tags to find the latest
+
+      - name: Compute next version
+        id: ver
+        run: |
+          latest=$(git tag --list 'v*' --sort=-v:refname | head -n1)
+          latest=${latest:-v0.0.0}
+          IFS=. read -r major minor patch <<< "${latest#v}"
+          case "${{ inputs.bump }}" in
+            major) major=$((major+1)); minor=0; patch=0 ;;
+            minor) minor=$((minor+1)); patch=0 ;;
+            patch) patch=$((patch+1)) ;;
+          esac
+          echo "tag=v$major.$minor.$patch" >> "$GITHUB_OUTPUT"
+
+      - name: Create GitHub Release
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh release create "${{ steps.ver.outputs.tag }}" \
+            --title "${{ steps.ver.outputs.tag }}" \
+            --generate-notes