fix(image): preserve embedInZpl when editing storage device/name

Device-selector and name-input both rebuilt storedAs as
{ device, name } without the existing embedInZpl flag. Silent
regression: a user setting recall-only (embedInZpl=false) and then
changing the device would silently flip back to the default (true),
re-emitting ~DY uploads the user explicitly opted out of.

Spread the existing storedAs so embedInZpl survives partial updates.

Author: u8array

src/registry/image.tsx

@@ -338,8 +338,8 @@ export const image: ObjectTypeDefinition<ImageProps> = {
                   onChange={(e) =>
                     onChange({
                       storedAs: {
+                        ...storedAs,
                         device: e.target.value as StorageDevice,
-                        name: storedAs.name,
                       },
                     })
                   }
@@ -363,7 +363,7 @@ export const image: ObjectTypeDefinition<ImageProps> = {
                     // is a clearer constraint signal than a tooltip.
                     if (!next) return;
                     onChange({
-                      storedAs: { device: storedAs.device, name: next },
+                      storedAs: { ...storedAs, name: next },
                     });
                   }}
                 />