Persist selected QR code color theme in invite friends dialog (#10892)

src/features/inviteFriends/hooks/useInviteThemeKey.ts

@@ -0,0 +1,14 @@
+import {device, useStorage} from '#/storage'
+import {INVITE_THEMES, type InviteThemeKey} from '../themes'
+
+/**
+ * Persisted color theme for the Invite Friends QR card (APP-2409). Falls back
+ * to 'day' when nothing is stored or the stored key is no longer a valid
+ * theme.
+ */
+export function useInviteThemeKey() {
+  const [stored, setThemeKey] = useStorage(device, ['inviteFriendsThemeKey'])
+  const themeKey: InviteThemeKey =
+    stored && stored in INVITE_THEMES ? stored : 'day'
+  return [themeKey, setThemeKey] as const
+}