test: add Playwright e2e tests for new features and uncovered workflows (#109)
High priority (new PR #108 features):
- Command palette: open/close, search flows, page navigation, FlowPilot handoff
- Fallback branches: add in editor, execute in session runner
- Session-to-flow: verify button appears on completed session detail
Medium priority (existing features without coverage):
- Procedural session: intake form, step-through, completion
- Tree editor: troubleshooting and procedural editor load/edit/save
- FlowPilot chat: page load, new chat creation
- Admin panel: dashboard, user management, settings access
Also adds API helpers: createProceduralTree(), createProceduralTreeWithFallbacks()
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>