The api client now catches network failures and non-JSON bodies robustly, and routes unexpected errors (offline / 5xx) to a global toast — 4xx stay with the caller so forms keep their inline messages. Toast actions are now optional (undo toasts keep their button; error toasts are message-only), and ToastHost moved from AppShell to the app root so toasts show everywhere, including the login screen. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm