Enable perf results PR comment on CI runs (#15748)

Author: iamAbhi-916

.github/workflows/perf-tests.yml

@@ -32,6 +32,7 @@ jobs:
     permissions:
       contents: read
       actions: read
+      pull-requests: write
 
     steps:
       # ── Setup ──────────────────────────────────────────────
@@ -83,6 +84,14 @@ jobs:
             packages/e2e-test-app-fabric/test/__perf__/**/__perf_snapshots__/
           retention-days: 30
 
+      # ── PR Comment ────────────────────────────────────────
+      - name: Post perf results to PR
+        if: github.event_name == 'pull_request' && always()
+        working-directory: packages/e2e-test-app-fabric
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: yarn perf:ci:report
+
       # ── Status Gate ────────────────────────────────────────
       - name: Check for regressions
         if: steps.compare.outcome == 'failure'