ci: auto-merge Dependabot PRs

.github/workflows/dependabot-automerge.yml

@@ -0,0 +1,41 @@
+name: Dependabot Auto-Merge
+
+on: pull_request
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  automerge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'dependabot[bot]'
+    steps:
+      - name: Fetch Dependabot metadata
+        id: metadata
+        uses: dependabot/fetch-metadata@v2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Auto-approve patch and minor updates
+        if: steps.metadata.outputs.update-type != 'version-update:semver-major'
+        run: gh pr review "$PR_URL" --approve -b "Auto-approved (dependabot ${{ steps.metadata.outputs.update-type }})"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Enable auto-merge for patch and minor updates
+        if: steps.metadata.outputs.update-type != 'version-update:semver-major'
+        run: gh pr merge "$PR_URL" --auto --squash
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Flag major updates for manual review
+        if: steps.metadata.outputs.update-type == 'version-update:semver-major'
+        run: |
+          gh pr comment "$PR_URL" --body "⚠️ **Major version bump detected** (${{ steps.metadata.outputs.dependency-names }}: ${{ steps.metadata.outputs.previous-version }} → ${{ steps.metadata.outputs.new-version }}). Skipping auto-merge — please review manually."
+          gh pr edit "$PR_URL" --add-label "major-update"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}