docs: Comprehensive documentation update for Dashboard V3 and Canvas

## Documentation Updates
- DASHBOARD.md: Updated to V3.0 with Canvas V3 features, file browser, introspection
- DASHBOARD_IMPLEMENTATION_STATUS.md: Marked Canvas V3 features as COMPLETE
- CANVAS.md: New comprehensive guide for Canvas Builder V3 with all features
- CLAUDE.md: Added dashboard quick reference and Canvas V3 features

## Canvas V3 Features Documented
- File Browser: Browse studies directory for model files
- Model Introspection: Auto-discover expressions, solver type, dependencies
- One-Click Add: Add expressions as design variables instantly
- Claude Bug Fixes: WebSocket reconnection, SQL errors resolved
- Health Check: /api/health endpoint for monitoring

## Backend Services
- NX introspection service with expression discovery
- File browser API with type filtering
- Claude session management improvements
- Context builder enhancements

## Frontend Components
- FileBrowser: Modal for file selection with search
- IntrospectionPanel: View discovered model information
- ExpressionSelector: Dropdown for design variable configuration
- Improved chat hooks with reconnection logic

## Plan Documents
- Added RALPH_LOOP_CANVAS_V2/V3 implementation records
- Added ATOMIZER_DASHBOARD_V2_MASTER_PLAN
- Added investigation and sync documentation

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

atomizer-dashboard/frontend/src/hooks/useChat.ts

@@ -4,10 +4,18 @@ import { ToolCall } from '../components/chat/ToolCallCard';
 
 export type ChatMode = 'user' | 'power';
 
+export interface CanvasState {
+  nodes: any[];
+  edges: any[];
+  studyName?: string;
+  studyPath?: string;
+}
+
 interface UseChatOptions {
   studyId?: string | null;
   mode?: ChatMode;
   useWebSocket?: boolean;
+  canvasState?: CanvasState | null;
   onError?: (error: string) => void;
 }
 
@@ -25,6 +33,7 @@ export function useChat({
   studyId,
   mode = 'user',
   useWebSocket = true,
+  canvasState: initialCanvasState,
   onError,
 }: UseChatOptions = {}) {
   const [state, setState] = useState<ChatState>({
@@ -37,6 +46,9 @@ export function useChat({
     isConnected: false,
   });
 
+  // Track canvas state for sending with messages
+  const canvasStateRef = useRef<CanvasState | null>(initialCanvasState || null);
+
   const abortControllerRef = useRef<AbortController | null>(null);
   const conversationHistoryRef = useRef<Array<{ role: string; content: string }>>([]);
   const wsRef = useRef<WebSocket | null>(null);
@@ -196,6 +208,10 @@ export function useChat({
         // Study context was updated - could show notification
         break;
 
+      case 'canvas_updated':
+        // Canvas state was updated - could show notification
+        break;
+
       case 'pong':
         // Heartbeat response - ignore
         break;
@@ -283,11 +299,12 @@ export function useChat({
         currentMessageRef.current = '';
         currentToolCallsRef.current = [];
 
-        // Send message via WebSocket
+        // Send message via WebSocket with canvas state
         wsRef.current.send(
           JSON.stringify({
             type: 'message',
             content: content.trim(),
+            canvas_state: canvasStateRef.current || undefined,
           })
         );
         return;
@@ -430,6 +447,21 @@ export function useChat({
     }
   }, []);
 
+  // Update canvas state (call this when canvas changes)
+  const updateCanvasState = useCallback((newCanvasState: CanvasState | null) => {
+    canvasStateRef.current = newCanvasState;
+
+    // Also send to backend to update context
+    if (useWebSocket && wsRef.current?.readyState === WebSocket.OPEN) {
+      wsRef.current.send(
+        JSON.stringify({
+          type: 'set_canvas',
+          canvas_state: newCanvasState,
+        })
+      );
+    }
+  }, [useWebSocket]);
+
   return {
     messages: state.messages,
     isThinking: state.isThinking,
@@ -442,5 +474,6 @@ export function useChat({
     clearMessages,
     cancelRequest,
     switchMode,
+    updateCanvasState,
   };
 }