refactor: merge QuickLaunch into CommandPalette, amber New Session button

- Remove QuickLaunch (lightning bolt) from TopBar — redundant with CommandPalette
- Delete QuickLaunch.tsx (dead code, no remaining imports)
- Add "New Project" to CommandPalette quick actions
- Change sidebar "New Session" button from cyan to amber-400

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/layout/CommandPalette.tsx

@@ -55,6 +55,7 @@ const ADMIN_PAGES: PaletteItem[] = [
 
 const QUICK_ACTIONS: PaletteItem[] = [
   { id: 'action-new-flow', group: 'quick-actions', title: 'Create New Flow', subtitle: 'Start from scratch or use AI', path: '/trees', icon: 'action' },
+  { id: 'action-new-project', group: 'quick-actions', title: 'New Project', subtitle: 'Create a step-by-step project', path: '/flows/new', icon: 'action' },
   { id: 'action-kb', group: 'quick-actions', title: 'Import from KB', subtitle: 'KB Accelerator', path: '/kb-accelerator', icon: 'action' },
   { id: 'action-scripts', group: 'quick-actions', title: 'Open Script Generator', subtitle: 'Generate automation scripts', path: '/scripts', icon: 'action' },
 ]