feat: add BlenderGen to toolbar menu

Added Blender 3D tool to the toolbar menu alongside Image and Video generation tools.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/ui/CustomToolbar.tsx

@@ -771,6 +771,14 @@ export function CustomToolbar() {
                 isSelected={tools["VideoGen"].id === editor.getCurrentToolId()}
               />
             )}
+            {tools["BlenderGen"] && (
+              <TldrawUiMenuItem
+                {...tools["BlenderGen"]}
+                icon="box"
+                label="Blender 3D"
+                isSelected={tools["BlenderGen"].id === editor.getCurrentToolId()}
+              />
+            )}
             {ENABLE_DRAWFAST && tools["Drawfast"] && (
               <TldrawUiMenuItem
                 {...tools["Drawfast"]}