feat: Add CI workflow for cloud E2E tests

- Create ci-tests-e2e-cloud.yaml workflow
- Manual trigger via workflow_dispatch
- Uses CLOUD_TEST_EMAIL and CLOUD_TEST_PASSWORD secrets
- Add CLOUD_TESTS.md documentation

browser_tests/tests/CLOUD_TESTS.md

@@ -0,0 +1,36 @@
+# Cloud E2E Tests
+
+## Setup
+
+Cloud tests run against `https://stagingcloud.comfy.org` with Firebase authentication.
+
+### Required GitHub Secrets
+
+Add these to repository settings → Secrets → Actions:
+
+- `CLOUD_TEST_EMAIL`: Firebase test account email
+- `CLOUD_TEST_PASSWORD`: Firebase test account password
+
+### Running Locally
+
+```bash
+# Set environment variables
+export CLOUD_TEST_EMAIL="your-test-email@example.com"
+export CLOUD_TEST_PASSWORD="your-password"
+
+# Run cloud tests
+pnpm exec playwright test --config=playwright.cloud.config.ts
+```
+
+### Running in CI
+
+Workflow: `.github/workflows/ci-tests-e2e-cloud.yaml`
+
+Trigger manually via Actions tab → "CI: Tests E2E Cloud" → Run workflow
+
+### Test Structure
+
+- Tests tagged with `@cloud` run only in cloud config
+- Auth handled once in `globalSetupCloud.ts`
+- Auth state saved to `browser_tests/.auth/cloudUser.json`
+- Cloud fixture in `fixtures/ComfyPageCloud.ts`