ci: add Copilot auto-review on new PRs (#70)

* ci: add Copilot auto-review on new PRs

Automatically requests GitHub Copilot as a reviewer when PRs are
opened or marked ready for review. Skips draft PRs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix: use REST API to request Copilot review

The gh CLI --add-reviewer flag treats 'copilot' as a regular user.
Use the REST API /requested_reviewers endpoint instead, which
properly handles the Copilot reviewer.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: imran-siddique

.github/workflows/copilot-review.yml

@@ -0,0 +1,24 @@
+name: Copilot Auto-Review
+
+on:
+  pull_request:
+    types: [opened, ready_for_review]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  copilot-review:
+    if: github.event.pull_request.draft == false
+    runs-on: ubuntu-latest
+    steps:
+      - name: Request Copilot Review
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          gh api \
+            --method POST \
+            -H "Accept: application/vnd.github+json" \
+            -H "X-GitHub-Api-Version: 2022-11-28" \
+            /repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/requested_reviewers \
+            -f "reviewers[]=copilot"