The fleet endpoint returned a bare 500, so the error banner only showed
"status code 500" with no cause. Wrap the call to log the full traceback
server-side and return the exception type, message and originating
file:line in the HTTP detail, so the dashboard banner pinpoints the
failure for an authenticated user.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>