ci: add auto-tag workflow for semantic versioning

Author: wilcorrea

.github/workflows/auto-tag.yml

@@ -0,0 +1,72 @@
+name: Auto Tag
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  auto-tag:
+    runs-on: ubuntu-latest
+    if: "!startsWith(github.event.head_commit.message, 'chore(release)') && !startsWith(github.event.head_commit.message, 'chore(homebrew)')"
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.PAT }}
+
+      - name: Calculate next version
+        id: version
+        run: |
+          LATEST_TAG=$(git tag --sort=-v:refname | grep '^v' | head -1)
+          [ -z "$LATEST_TAG" ] && LATEST_TAG="v0.0.0"
+          echo "latest=$LATEST_TAG"
+
+          VERSION="${LATEST_TAG#v}"
+          IFS='.' read -r MAJOR MINOR PATCH <<< "$VERSION"
+
+          COMMITS=$(git log "${LATEST_TAG}..HEAD" --pretty=format:"%s" 2>/dev/null)
+          if [ -z "$COMMITS" ]; then
+            echo "No commits since $LATEST_TAG"
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          BUMP="none"
+          while IFS= read -r msg; do
+            if echo "$msg" | grep -qiE "^[a-z]+(\(.+\))?!:|BREAKING CHANGE"; then
+              BUMP="major"
+              break
+            elif echo "$msg" | grep -qE "^feat(\(.+\))?:"; then
+              [ "$BUMP" != "major" ] && BUMP="minor"
+            elif echo "$msg" | grep -qE "^(fix|perf|refactor|build)(\(.+\))?:"; then
+              [ "$BUMP" = "none" ] && BUMP="patch"
+            fi
+          done <<< "$COMMITS"
+
+          if [ "$BUMP" = "none" ]; then
+            echo "No releasable commits found"
+            echo "skip=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+
+          case "$BUMP" in
+            major) MAJOR=$((MAJOR + 1)); MINOR=0; PATCH=0 ;;
+            minor) MINOR=$((MINOR + 1)); PATCH=0 ;;
+            patch) PATCH=$((PATCH + 1)) ;;
+          esac
+
+          NEXT="${MAJOR}.${MINOR}.${PATCH}"
+          {
+            echo "next=$NEXT"
+            echo "tag=v$NEXT"
+            echo "skip=false"
+          } >> "$GITHUB_OUTPUT"
+          echo "Bump: $BUMP ($LATEST_TAG -> v$NEXT)"
+
+      - name: Create and push tag
+        if: steps.version.outputs.skip != 'true'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git tag -a "${{ steps.version.outputs.tag }}" -m "${{ steps.version.outputs.tag }}"
+          git push origin "${{ steps.version.outputs.tag }}"