The TTP worker subscribes to attacker.session.ended but no upstream
component published it — the rule pack (R0001–R0030) therefore never
fired on live SSH traffic even after the consume-side wiring landed
in E.3.18a/b/c.
The collector now hosts a per-attacker_ip command index
(_SessionAggregator) that watches the same parsed-event stream as
_publish_log. Shell `command` events are appended to a per-IP list;
on `session_recorded` the aggregator slices the list to commands
inside the [ended_at - duration_s, ended_at] window and publishes
attacker.session.ended with the session metadata + commands list.
The TTP worker's _build_events fan-out (E.3.18b) turns each command
into a source_kind="command" TaggerEvent that the RuleEngineTagger
(E.3.18c) matches against R0001–R0030.
Memory bound: per-IP entries TTL-evict at DECNET_COLLECTOR_SESSION_AGG_TTL_SEC
(default 3600 s). Publish failures are swallowed in the aggregator —
a misbehaving bus cannot stall the per-container stream threads.