chore(ui): Add jest/swc transform cache to frontend-optional workflow (#113086)

Mirrors the cache step from `frontend.yml`

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: scttcper

.github/workflows/frontend-optional.yml

@@ -90,6 +90,17 @@ jobs:
 
       - uses: ./.github/actions/setup-node-pnpm
 
+      - name: jest transform cache
+        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
+        with:
+          path: |
+            .cache/jest
+            ~/.cache/swc
+          key: jest-cache-${{ runner.os }}-${{ hashFiles('pnpm-lock.yaml', 'jest.config.ts') }}-${{ matrix.instance }}
+          restore-keys: |
+            jest-cache-${{ runner.os }}-${{ hashFiles('pnpm-lock.yaml', 'jest.config.ts') }}-
+            jest-cache-${{ runner.os }}-
+
       - name: Download jest-balance.json
         id: download-artifact
         uses: dawidd6/action-download-artifact@ac66b43f0e6a346234dd65d4d0c8fbb31cb316e5 # v11