/**
 * SIP feature flag helpers — shared between server and client builds.
 *
 * On the server: read FEATURE_SIP_ENABLED at runtime from process.env.
 * On the client: rely on the `/api/telephone/sip/feature` endpoint that returns
 *   `{ enabled: boolean }` so the bundle never bakes in the env value.
 */
export function isSipFeatureEnabled(): boolean {
  const v = (process.env.FEATURE_SIP_ENABLED || '').toLowerCase().trim();
  return v === '1' || v === 'true' || v === 'yes' || v === 'on';
}