- useEditorSetup() / useEditorSetupWithClear() in tests/e2e/fixtures.ts
- Migrated 17 specs to shared fixture, removing ~300 lines of boilerplate
- Moved getSelectedNode/getSelectedNodes to shared store helpers
- Replaced inline getSelectedNode in 4 specs with shared import
- Test duplication: 329 → 308 clones (10.12% → 9.08%)