Fix: Handle image removal in product editor

- Add support for removeImage/removeImageBack flags in updateProduct action
- When Remove button is clicked, client sets isRemoved=true to hide UI
- Server action checks removeImage/removeImageBack form fields and sets imageUrl/imageUrlBack to null
- Also reset printArea to default when image is removed
- Tested: Remove button now successfully clears images and persists changes to database

src/app/admin/products/actions.ts

@@ -268,9 +268,12 @@ export async function updateProduct(formData: FormData) {
     weightGrams,
   };
 
-  // Only touch the front photo/print area if a new photo was actually uploaded —
-  // otherwise leave whatever's already there alone.
-  if (imageFile && imageFile.size > 0) {
+  // Handle front photo: new upload, removal, or keep existing
+  const removeImage = String(formData.get('removeImage') ?? '') === '1';
+  if (removeImage) {
+    data.imageUrl = null;
+    data.printArea = JSON.stringify(DEFAULT_PRINT_AREAS[mockup] ?? DEFAULT_PRINT_AREAS.tshirt);
+  } else if (imageFile && imageFile.size > 0) {
     data.imageUrl = await fileToDataUrl(imageFile);
 
     const hasCustomPrintArea = String(formData.get('hasCustomPrintArea') ?? '') === '1';
@@ -286,7 +289,12 @@ export async function updateProduct(formData: FormData) {
     );
   }
 
-  if (imageBackFile && imageBackFile.size > 0) {
+  // Handle back photo: new upload, removal, or keep existing
+  const removeImageBack = String(formData.get('removeImageBack') ?? '') === '1';
+  if (removeImageBack) {
+    data.imageUrlBack = null;
+    data.printAreaBack = null;
+  } else if (imageBackFile && imageBackFile.size > 0) {
     data.imageUrlBack = await fileToDataUrl(imageBackFile);
 
     const hasCustomPrintAreaBack = String(formData.get('hasCustomPrintAreaBack') ?? '') === '1';