Expose showBranding as read-only GraphQL field and reflect it in theme preview

Uses the Loader + Page + Fragment pattern so the snippet page fetches
its own data instead of relying on Outlet context.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/server/api/console/v1/graphql/cookie_banner.graphql

@@ -84,6 +84,7 @@ type CookieBanner implements Node {
     privacyPolicyUrl: String!
     consentExpiryDays: Int!
     consentMode: CookieConsentMode!
+    showBranding: Boolean!
 
     organization: Organization @goField(forceResolver: true)
 

pkg/server/api/console/v1/types/cookie_banner.go

@@ -72,6 +72,7 @@ func NewCookieBanner(b *coredata.CookieBanner) *CookieBanner {
 		PrivacyPolicyURL:  b.PrivacyPolicyURL,
 		ConsentExpiryDays: b.ConsentExpiryDays,
 		ConsentMode:       b.ConsentMode,
+		ShowBranding:      b.ShowBranding,
 		CreatedAt:         b.CreatedAt,
 		UpdatedAt:         b.UpdatedAt,
 	}