feat(dashboard): Enhanced chat, spec management, and Claude integration

Backend:
- spec.py: New AtomizerSpec REST API endpoints
- spec_manager.py: SpecManager service for unified config
- interview_engine.py: Study creation interview logic
- claude.py: Enhanced Claude API with context
- optimization.py: Extended optimization endpoints
- context_builder.py, session_manager.py: Improved services

Frontend:
- Chat components: Enhanced message rendering, tool call cards
- Hooks: useClaudeCode, useSpecWebSocket, improved useChat
- Pages: Updated Dashboard, Analysis, Insights, Setup, Home
- Components: ParallelCoordinatesPlot, ParetoPlot improvements
- App.tsx: Route updates for canvas/studio

Infrastructure:
- vite.config.ts: Build configuration updates
- start/stop-dashboard.bat: Script improvements

atomizer-dashboard/frontend/src/components/ParallelCoordinatesPlot.tsx

@@ -26,8 +26,8 @@ interface DesignVariable {
   name: string;
   parameter?: string;  // Optional: the actual parameter name if different from name
   unit?: string;
-  min: number;
-  max: number;
+  min?: number;
+  max?: number;
 }
 
 interface Constraint {