Update review workflow to use Gemini API

switch back to gemini due to claude being temporarily maxed out

Author: alexanderlhicks

.github/workflows/review.yml

@@ -85,9 +85,9 @@
         - uses: alexanderlhicks/lean-review-workflow@main
           with:
             github_token: ${{ secrets.GITHUB_TOKEN }}
-            api_key: ${{ secrets.CLAUDE_API_KEY }}
-            provider: anthropic
-            model: claude-opus-4-7
+            api_key: ${{ secrets.GEMINI_API_KEY }}
+            provider: gemini
+            model: gemini-3.1-pro-preview
             pr_number: ${{ github.event.issue.number || github.event.pull_request.number }}
             external_refs: "${{ steps.get_args.outputs.external_refs }}"
             repo_context_refs: "${{ steps.get_args.outputs.repo_context_refs }}"