Support agent-scheduled monitoring for direct SSH runs #790

Frequent status checks and log collection add unnecessary remote requests and local disk activity for long-running SSH experiments, especially through jump hosts.

Add an optional on-demand monitoring mode for direct SSH runs:

• Let agents schedule orx refresh <runId> and collect logs with --collect-logs.
• Preserve automatic monitoring defaults and support configurable intervals.
• Persist each run's policy across restarts, with reliable cancellation and minimal UI refresh controls.

Settings should apply to newly submitted runs.

Related: #713, #699, #741.