test(coding-agent): machine-form swarm executor tests

Cover the state-machine semantics end to end with the fake host: a
three-round review loop (guarded switch approved=false twice then true;
3 reviewing entries, 2 fixing entries, done), a mutually exclusive guard
switch where only the matching branch enters, fan-out from one settle,
max_entries blocking recorded as transition_blocked events with a
quiescent done, a self-loop re-entering until its guard fails, wait-state
settles from a completed path watch and from the injectable-clock timeout
(event object bound into the dependent prompt), a max_transitions pause
reported once and resumed, and stop() cancelling an active watch.

Author: sethkarten

prime-agent-runtime/src/rlm/swarm.py

@@ -1418,6 +1418,7 @@ async def _evaluate_settles(self, run: SwarmRun) -> None:
                             f"state {target.state_id!r} is at max_entries "
                             f"{target.max_entries}; transition {state_id!r} -> {target.state_id!r} blocked"
                         ),
+                        **{"from": state_id, "to": target.state_id},
                     )
                     continue
                 if run.transitions_fired >= run.max_transitions and not run.max_transitions_reported: