Add queue get, export and single-entry retry

Stations that run offline queue their runs locally, and operators needed better tools to inspect, recover, and clean up stuck uploads from the CLI.

• Added queue get and queue export to inspect a queued run's failure detail and archive its upload payload before removing it
• Added single-entry retry that reports the created run ID or the persisted failure record with --json, and exit codes that signal when entries remain queued
• Renamed queue drop to queue rm and added lifecycle status (parked, backoff, attachments pending) plus attempt counts to queue ls