fix(ci): load all examples for Playwright E2E tests

**Problem**: Playwright duplicate test fails in CI because
`members_channels_2` dataset is not loaded with `--load-test-data` flag.

The `--load-test-data` flag only loads files matching `*.test.*` pattern
(e.g., `unicode_test.test.yaml`). Regular example datasets like
`members_channels_2.yaml` are skipped, causing the duplicate dataset
test to fail with null.

**Root Cause**:
- CI uses `superset load_examples --load-test-data` (line 115 in bashlib.sh)
- This loads ONLY `*.test.*` files (1 dataset: unicode_test)
- Playwright test expects `members_channels_2` virtual dataset
- Ephemeral environments use `superset load_examples` (all datasets)

**Solution**: Create separate data loading function for Playwright

1. Added `playwright_testdata()` function in bashlib.sh:
   - Loads ALL examples via `superset load_examples` (no flag)
   - Includes all 17 datasets (16 virtual + 1 test)
   - Matches ephemeral environment behavior

2. Updated superset-e2e.yml:
   - Playwright job now uses `playwright_testdata` instead of `testdata`
   - Cypress tests still use `testdata` (unchanged)

**Impact**:
- ✅ Playwright tests can use realistic example datasets
- ✅ Matches ephemeral environment data availability
- ✅ No impact on Cypress tests (still use --load-test-data)
- ⏱️ CI data loading ~30-60s slower (acceptable tradeoff)

**Testing**: Will be validated by CI run after push

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/bashlib.sh

@@ -117,6 +117,19 @@ testdata() {
   say "::endgroup::"
 }
 
+playwright_testdata() {
+  cd "$GITHUB_WORKSPACE"
+  say "::group::Load all examples for Playwright tests"
+  # must specify PYTHONPATH to make `tests.superset_test_config` importable
+  export PYTHONPATH="$GITHUB_WORKSPACE"
+  pip install -e .
+  superset db upgrade
+  superset load_test_users
+  superset load_examples
+  superset init
+  say "::endgroup::"
+}
+
 celery-worker() {
   cd "$GITHUB_WORKSPACE"
   say "::group::Start Celery worker"

.github/workflows/superset-e2e.yml

@@ -223,7 +223,7 @@ jobs:
         if: steps.check.outputs.python || steps.check.outputs.frontend
         uses: ./.github/actions/cached-dependencies
         with:
-          run: testdata
+          run: playwright_testdata
       - name: Setup Node.js
         if: steps.check.outputs.python || steps.check.outputs.frontend
         uses: actions/setup-node@v5