ci: auto-approve and merge Renovate PRs (#239)

Signed-off-by: Jose Colella <jose.colella@gusto.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: josecolella

.github/workflows/auto-merge-renovate.yml

@@ -0,0 +1,25 @@
+name: Auto-merge Renovate PRs
+
+on:
+  pull_request_target:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  auto-merge:
+    runs-on: ubuntu-latest
+    if: github.actor == 'renovate[bot]'
+    steps:
+      - name: Approve PR
+        run: gh pr review --approve "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Enable auto-merge
+        run: gh pr merge --auto --squash "$PR_URL"
+        env:
+          PR_URL: ${{ github.event.pull_request.html_url }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

renovate.json

@@ -5,5 +5,6 @@
     ":automergeStableNonMajor",
     "security:minimumReleaseAgeNpm"
   ],
-  "semanticCommits": "enabled"
+  "semanticCommits": "enabled",
+  "platformAutomerge": true
 }