ci(runner): retry Chromium installation

.github/workflows/runner-full-stack-e2e.yml

@@ -363,7 +363,18 @@ jobs:
         run: pnpm --filter @paperclipai/paperclip-runner build:runner-binaries
 
       - name: Install Chromium
-        run: pnpm exec playwright install --with-deps chromium
+        run: |
+          set -euo pipefail
+          for attempt in 1 2 3; do
+            if pnpm exec playwright install --with-deps chromium; then
+              exit 0
+            fi
+            if [ "$attempt" -eq 3 ]; then
+              echo "Chromium installation failed after $attempt attempts." >&2
+              exit 1
+            fi
+            sleep "$((attempt * 10))"
+          done
 
       - name: Run paid cell
         env: