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/backend/api/services/__init__.py

@@ -3,5 +3,13 @@ Atomizer Dashboard Services
 """
 
 from .claude_agent import AtomizerClaudeAgent
+from .spec_manager import SpecManager, SpecManagerError, SpecNotFoundError, SpecConflictError, get_spec_manager
 
-__all__ = ['AtomizerClaudeAgent']
+__all__ = [
+    'AtomizerClaudeAgent',
+    'SpecManager',
+    'SpecManagerError',
+    'SpecNotFoundError',
+    'SpecConflictError',
+    'get_spec_manager',
+]