ci: report required Scorecard analysis on pull requests

.github/workflows/scorecard-pr.yml

@@ -0,0 +1,38 @@
+name: Scorecard PR
+
+on:
+  pull_request:
+    branches:
+      - main
+
+# PRs use Scorecard's local-checkout mode. Repository-wide checks and badge /
+# SARIF publication remain in bytefolk-scorecard.yml on the default branch.
+# Do not use pull_request_target or give this job publication credentials.
+permissions:
+  contents: read
+
+jobs:
+  scorecard:
+    name: OpenSSF Scorecard
+    runs-on: ubuntu-24.04
+    timeout-minutes: 15
+    steps:
+      - name: Check out PR merge commit
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Analyze PR checkout
+        uses: ossf/scorecard-action@2d1146689b8cda280b9bc96326124645441f03bc # v2.4.4
+        with:
+          results_file: results.sarif
+          results_format: sarif
+          publish_results: false
+
+      - name: Upload PR Scorecard report
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: scorecard-pr-results
+          path: results.sarif
+          if-no-files-found: error
+          retention-days: 14