Dio throws DioException for 4xx responses by default, so a server
returning 401 on /api/auth/status (correct behaviour for an
unauthenticated request) was caught and shown as "Could not reach
server", preventing the URL from ever being saved.
Set validateStatus: (_) => true so any HTTP response (200, 401, 404…)
counts as "reachable". Only actual network failures (no response) now
trigger the error message.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>