Marks a single auto-triage work-item as BLOCKED on its OWN tracker when a run hit something it could not overcome (permission denial, broken environment, timeout, unrecoverable error). Applies the `triage-blocked` label, returns the item to the queue (Todo), and comments the reason — so it leaves the auto-queue until a human resolves the cause and clears the label. Tracker- and project-agnostic: reuses the triage config + tracker binding (Linear, GitHub, …), never assumes one. The daemon calls it after DETERMINISTICALLY detecting a block; also usable as `triage-block <ITEM-ID> -- <reason>`.