Preview + save UI for bulk-add tool

still not wired up tho!

src/app/WardrobePage/support/AllItemLayersSupportModal.js

@@ -261,6 +261,16 @@ function AllItemLayersSupportModalContent({ item, bulkAddProposal }) {
   });
 
   return (
+    <Box>
+      {bulkAddProposalData && (
+        <Flex align="center" marginBottom="6">
+          <Heading size="md">Previewing bulk-add changes</Heading>
+          <Box flex="1 0 auto" width="4" />
+          <Button size="sm" colorScheme="green">
+            Save {bulkAddProposalData.layersToAdd.length} changes
+          </Button>
+        </Flex>
+      )}
       <Wrap justify="center" spacing="4">
         {itemAppearances.map((itemAppearance) => (
           <WrapItem key={itemAppearance.id}>
@@ -268,6 +278,7 @@ function AllItemLayersSupportModalContent({ item, bulkAddProposal }) {
           </WrapItem>
         ))}
       </Wrap>
+    </Box>
   );
 }