fix(issue-18): bind the heartbeat timer to the agent process; scope started to the attempt; ignore re-sent finished dispatches

Review round 1 (claude NOT PASS) corrections:
- B2: the timer now watches a process - `--watch-pid`, or by default the
  nearest agent-CLI ancestor of the publishing command - and stops within
  one period once it is gone, so a crashed agent stops heartbeating and is
  closed after K x N; a remote runner watches itself. Documented as process
  liveness (an alive-but-stuck agent keeps heartbeating).
- R1: `_wait_started` accepts an events.log `started` only when it carries
  the current dispatch token (loop jobs share one events.log).
- R2: the remote runner ignores a re-sent dispatch of an attempt that
  already reached its terminal.
- R3: registry.md EOF blank line (git diff --check clean).
- R4: the ack error states the effective budget when the wall clock cut it.
- P3: stop_timer verifies the pidfile pid is this job's timer before
  signalling; a retained state message keeps its own seq watermark so it
  can never make the monotonic guard drop its own event.
- MULTI_AGENT_RULES.md timeout section updated for the contract.
- tests: agent-process death stops the timer, recycled-pid safety,
  attempt-scoped started, re-sent dispatch; acceptance 3 now kills the
  agent process instead of the timer. Help captures refreshed
  (--watch-pid). The wrapper can be sourced with
  MAM_DELEGATE_JOB_NO_MAIN=1 for helper-level tests.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

.agents/skills/lib_py/delegation/job_subscriber.py

@@ -139,6 +139,7 @@ class _Watcher:
         # gap is only meaningful after that - the initial last_seq comes from
         # the registry and may be behind the wire (or ahead of a fresh remote).
         self.accepted_any: Set[str] = set()
+        self.state_seq: Dict[str, int] = {}
 
     def _note_seq_gap(self, jid: str, expected: int, got: int, via: str, topic: str) -> None:
         """Issue #18: a seq the subscriber never saw is a detected loss."""
@@ -161,11 +162,14 @@ class _Watcher:
         if not isinstance(seq, int):
             logger.warning("drop state for job %s: missing or invalid seq", jid)
             return
-        last = self.last_seq.get(jid, 0)
+        # A state message never advances the event watermark: MQTT orders
+        # messages per connection, not across topics, so a state that overtakes
+        # its own event must not make the monotonic guard drop that event.
+        last = max(self.last_seq.get(jid, 0), self.state_seq.get(jid, 0))
         if jid in self.accepted_any and seq > last + 1:
             self._note_seq_gap(jid, last + 1, seq, "state", msg.topic)
-        if seq > last:
-            self.last_seq[jid] = seq
+        if seq > self.state_seq.get(jid, 0):
+            self.state_seq[jid] = seq
         mqtt_common.append_event(jid, {
             "event": "received",
             "source_event": STATE_EVENT,