Hide customer action buttons (Submit/Add to bag) when in admin editing mode

Added isAdminEditing prop to DesignCanvas component. When true, hides the
"Submit for Approval" and "Add to bag" buttons since these are customer-facing
actions. The admin edit page now only shows the design canvas and the
"Send to Customer for Review" button.

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

src/app/admin/designs/[id]/edit/page.tsx

@@ -109,7 +109,7 @@ export default function EditDesignPage({ params }: { params: { id: string } }) {
         </div>
 
         {/* Full Design Canvas */}
-        <DesignCanvas product={design.product} />
+        <DesignCanvas product={design.product} isAdminEditing={true} />
       </div>
     </div>
   );

src/components/DesignCanvas.tsx

@@ -487,7 +487,7 @@ function generateCurvePath(type: string, radius: number, reverse: boolean = fals
   return path;
 }
 
-export default function DesignCanvas({ product }: { product: ProductDTO }) {
+export default function DesignCanvas({ product, isAdminEditing = false }: { product: ProductDTO; isAdminEditing?: boolean }) {
   const [color, setColor] = useState(product.colors[0]);
   const [size, setSize] = useState<string | null>(product.sizes[0] ?? null);
   const [designWidthCm, setDesignWidthCm] = useState<number | null>(null);
@@ -1498,7 +1498,7 @@ export default function DesignCanvas({ product }: { product: ProductDTO }) {
                 +
               </button>
             </div>
-            {approvalStatus === 'APPROVED' ? (
+            {!isAdminEditing && (approvalStatus === 'APPROVED' ? (
               <button
                 onClick={handleAddToBag}
                 disabled={elementsFront.length === 0 && elementsBack.length === 0}
@@ -1522,7 +1522,7 @@ export default function DesignCanvas({ product }: { product: ProductDTO }) {
               >
                 {submittingForApproval ? 'Submitting…' : 'Submit for Approval'}
               </button>
-            )}
+            ))}
           </div>
           {elementsFront.length === 0 && elementsBack.length === 0 && !approvalStatus && (
             <p className="text-xs text-splash-pink">Add text or images to personalize your design before submitting</p>