feat(get-user): emit brand_chrome for Hamkar brandManaged opt-in

Expose brand_chrome so apps apply header/menu/body colors only after SuperAdmin color save.

Co-authored-by: Cursor <cursoragent@cursor.com>

prisma/backfill-appearance-from-registry.ts

@@ -207,11 +207,13 @@ async function main() {
 
     if (tenant.product === 'hamkar') {
       const managed = existingUi?.kind === 'hamkar' && existingUi?.settingsManaged === true
+      const brandManaged = existingUi?.kind === 'hamkar' && existingUi?.brandManaged === true
       const built = buildHamkarUiFromBrand({
         primaryColor: primary,
         secondaryColor: secondary,
         backgroundColor: background,
         settingsManaged: managed,
+        brandManaged,
         registryMode: registryMode || existingUi?.registryMode || 'dynamicMode',
         settings: managed ? existingUi.settings : undefined,
       })