Add customize-screen shop preview and purchase flow.

Locked items can be previewed on the pet from the editor, purchased with points in the preview modal, and opened in the full customize view from the shop.

components/pet/room-background-picker.tsx

@@ -13,6 +13,7 @@ type RoomBackgroundPickerProps = {
   value: RoomBackgroundId;
   ownedItemIds: string[];
   onChange: (roomId: RoomBackgroundId) => void;
+  onLockedSelect?: (roomId: RoomBackgroundId) => void;
   compact?: boolean;
 };
 
@@ -20,6 +21,7 @@ export function RoomBackgroundPicker({
   value,
   ownedItemIds,
   onChange,
+  onLockedSelect,
   compact = false,
 }: RoomBackgroundPickerProps) {
   return (
@@ -47,14 +49,20 @@ export function RoomBackgroundPicker({
             <button
               key={room.id}
               type="button"
-              disabled={!unlocked}
               aria-pressed={selected}
               title={
                 unlocked
                   ? room.name
-                  : `${room.name} — unlock in the shop`
+                  : `${room.name} — preview in shop`
               }
-              onClick={() => onChange(room.id)}
+              onClick={() => {
+                if (!unlocked) {
+                  onLockedSelect?.(room.id);
+                  return;
+                }
+
+                onChange(room.id);
+              }}
               className={cn(
                 "relative aspect-[4/3] overflow-hidden border-2 transition-transform",
                 selected
@@ -62,7 +70,7 @@ export function RoomBackgroundPicker({
                   : "border-border/70",
                 unlocked
                   ? "hover:-translate-y-0.5"
-                  : "cursor-not-allowed opacity-80",
+                  : "opacity-80 hover:-translate-y-0.5",
               )}
             >
               <div className={cn("absolute inset-0", room.previewClassName)} />