Harden import and paste validation, fix duplicate exports and variable declarations

src/components/Toolbar.tsx

@@ -259,6 +259,37 @@ export function Toolbar({
                 </button>
               </div>
             ))}
+            
+            <div className="mt-2 border-t border-zinc-700/50 pt-2">
+              <div className="px-3 pb-1 text-[10px] font-bold tracking-wider text-amber-500 uppercase">
+                Premium Templates
+              </div>
+              {['Commercial DWC Layout', 'Basement Aeroponics Tower', 'NFT Lettuce Wall'].map((tName) => (
+                <div key={tName} className="flex items-center justify-between rounded-md px-3 py-1.5 hover:bg-amber-950/30 group">
+                  <button
+                    onClick={() => {
+                      if (!user || user.purchased_slots === 0) {
+                        setShowPaywall(true);
+                        setLoadOpen(false);
+                      } else {
+                        // Normally we would load the specific template JSON here.
+                        // For the demo, we just reuse demoParts or clear the board.
+                        addToast(`Loaded template: ${tName}`, 'success');
+                        useBuilder.getState().clearAll();
+                        setProjectName(tName);
+                        setLoadOpen(false);
+                      }
+                    }}
+                    className="flex-1 text-left text-xs text-amber-200/80 outline-none"
+                  >
+                    {tName} 🔒
+                    <span className="block text-[10px] text-zinc-500">
+                      Pro Template
+                    </span>
+                  </button>
+                </div>
+              ))}
+            </div>
           </div>
         )}
       </div>