feat: enhance canvas components with improved sidebar and toolbar functionality

- Updated CanvasSidebar to accept canvasId as a prop, enabling dynamic content based on the current canvas.
- Refactored CanvasToolbar to implement a dropdown menu for adding nodes, improving usability and organization.
- Introduced new node types and updated existing ones in the node template picker for better categorization and searchability.
- Enhanced AssetNode to utilize context for asset browser interactions, streamlining asset management on the canvas.
- Improved overall layout and styling for better user experience across canvas components.

components/dashboard/recent-transactions.tsx

@@ -87,7 +87,7 @@ export function RecentTransactions() {
               Noch keine Aktivität
             </p>
             <p className="mt-1 text-xs text-muted-foreground/70">
-              Erstelle dein erstes KI-Bild im Canvas
+              Erstelle dein erstes Bild im Canvas (Prompt-Knoten)
             </p>
           </div>
         </div>