fix: add validation and diagnostics for API settings transform

Add explicit checks for required TranslatedField wrapper structure
and throw descriptive errors with actual API response data when
fields are missing. This will help diagnose why the user context
API is failing despite returning 200 status.

src/lib/types.ts

@@ -324,6 +324,17 @@ export interface UserSettings {
  * Extracts the .value property from each TranslatedField.
  */
 export function transformApiSettings(apiSettings: ApiUserSettingsResponse): UserSettings {
+  // Validate that all required fields with TranslatedField wrappers are present
+  if (!apiSettings.onboarding?.value) {
+    throw new Error('API settings missing required field: onboarding.value. Received: ' + JSON.stringify(apiSettings));
+  }
+  if (!apiSettings.default_remote_sport) {
+    throw new Error('API settings missing required field: default_remote_sport. Received: ' + JSON.stringify(apiSettings));
+  }
+  if (!apiSettings.default_remote_member_id) {
+    throw new Error('API settings missing required field: default_remote_member_id. Received: ' + JSON.stringify(apiSettings));
+  }
+
   return {
     onboarding: apiSettings.onboarding.value,
     default_remote_sport: apiSettings.default_remote_sport.value,