feat: enhance dashboard and canvas components with improved state management and resizing logic

- Added client mount state to the dashboard to prevent premature interactions before the component is fully loaded.
- Updated button disabling logic to ensure it reflects the component's readiness and user session state.
- Introduced zIndex handling in canvas placement context for better node layering.
- Enhanced asset and image nodes with improved resizing logic to maintain aspect ratios during adjustments.
- Refactored node components to streamline rendering and improve performance during dynamic updates.

components/canvas/nodes/ai-image-node.tsx

@@ -166,7 +166,7 @@ export default function AiImageNode({
     <BaseNodeWrapper
       nodeType="ai-image"
       selected={selected}
-      className="flex h-full w-full min-h-0 min-w-0 flex-col overflow-hidden"
+      className="flex h-full w-full min-h-0 min-w-0 flex-col"
     >
       <Handle
         type="target"