feat: Update layout management in TerminalGrid to use updateLayoutSizes for size changes

ccw/frontend/src/components/terminal-dashboard/TerminalGrid.tsx

@@ -80,13 +80,13 @@ function GridGroupRenderer({ group, minSize, onSizeChange }: GridGroupRendererPr
 export function TerminalGrid({ className }: { className?: string }) {
   const layout = useTerminalGridStore(selectTerminalGridLayout);
   const panes = useTerminalGridStore(selectTerminalGridPanes);
-  const setLayout = useTerminalGridStore((s) => s.setLayout);
+  const updateLayoutSizes = useTerminalGridStore((s) => s.updateLayoutSizes);
 
   const handleSizeChange = useCallback(
     (sizes: number[]) => {
-      setLayout({ ...layout, sizes });
+      updateLayoutSizes(sizes);
     },
-    [layout, setLayout]
+    [updateLayoutSizes]
   );
 
   const content = useMemo(() => {

ccw/frontend/src/stores/terminalGridStore.ts

@@ -31,6 +31,7 @@ export interface TerminalGridState {
 
 export interface TerminalGridActions {
   setLayout: (layout: AllotmentLayoutGroup) => void;
+  updateLayoutSizes: (sizes: number[]) => void;
   splitPane: (paneId: PaneId, direction: 'horizontal' | 'vertical') => PaneId;
   closePane: (paneId: PaneId) => void;
   assignSession: (paneId: PaneId, sessionId: string | null) => void;
@@ -82,6 +83,14 @@ export const useTerminalGridStore = create<TerminalGridStore>()(
           set({ layout }, false, 'terminalGrid/setLayout');
         },
 
+        updateLayoutSizes: (sizes) => {
+          const currentLayout = get().layout;
+          // Only update if sizes actually changed
+          if (JSON.stringify(currentLayout.sizes) !== JSON.stringify(sizes)) {
+            set({ layout: { ...currentLayout, sizes } }, false, 'terminalGrid/updateLayoutSizes');
+          }
+        },
+
         splitPane: (paneId, direction) => {
           const state = get();
           const newPaneId = generatePaneId(state.nextPaneIdCounter);