b792bd0529
Completes #51690 on top of the salvaged #60378 timeout metadata: - async_delegation: terminal 'stalled' events now carry structured stall context (stalled_after_quiet_seconds, stall_threshold_seconds, stall_phase idle|in_tool, stall_grace_seconds) on both single and batch paths, persisted in the durable row so restart-restored events keep it. Mirrors the sync path's timeout_seconds/timed_out_after_ seconds/timeout_phase from #60378. - list_async_delegations(): exposes seconds_since_progress and live children_activity (per-child api_calls, current_tool, seconds_since_activity) sampled from the dispatch's progress_fn outside the records lock; private monitor bookkeeping and callables never leak. - /agents (CLI + gateway): background delegations render per-child activity rows, quiet-time hints, and the stalling state; gateway section is new (previously async delegations were invisible there). New locale key gateway.agents.background_delegations in all 17 catalogs. Tests: stall-metadata event shape, live-listing projection, gateway /agents rendering (real registry dispatch, sabotage-verified), sync timeout metadata fields, non-timeout None contract.