feat(issue-33): the job budget travels and the two clocks carry different labels

- wrapper: TIMEOUT falls back to MAM_JOB_TIMEOUT_S (--timeout > env > 3600);
  an invalid value warns and keeps 3600.
- loop: --job-timeout <sec> (run_loop.sh passes it on; refused in the legacy
  shell loop). The runner always hands the wrapper --timeout, so the budget
  the wrapper registers is the one its wait caps come from.
- runner: wait_for_job and the MAM_CHILD_WAIT_S default are budget + 300 s
  (MAM_WAIT_GRACE_S), today's 3900 with no option; an explicit
  MAM_CHILD_WAIT_S still wins.
- subscriber: the wall-clock budget returns 4 (RC_WALL_CLOCK), silence keeps
  2 (RC_NO_EVENT). The wrapper maps both to caller rc 2 and labels the close
  from the rc: wall_clock_timeout vs deadline_timeout; the disk-heartbeat
  grace that ends on the deadline is the wall clock too.
- registry close accepts wall_clock_timeout (engine: -> error); the remote
  runner's deadline and command-timeout details lead with wall_clock_timeout;
  the sub-job table files it CLOSED-UNCONFIRMED (first token, colon stripped).

Test expectations changed only where the contract changed: the loop's
contract_args now starts with --timeout, the subscriber's exit-code docstring
names rc 2/4, and the registry --help capture lists the new close kind.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_issue18_liveness_contract.py

@@ -1286,7 +1286,9 @@ def test_loop_runner_passes_the_contract_and_remote_label(tmp_path, monkeypatch)
     r.parse_args()
     assert r.session_label("creator-claude-01") == "herdr:creator-claude-01"
     assert r.session_label("reviewer-far-01") == "remote:reviewer-far-01"
-    assert r.contract_args() == ["--heartbeat", "20", "--heartbeat-misses", "3", "--ack-timeout", "45"]
+    # Issue #33: the job budget is always passed explicitly (default 3600)
+    assert r.contract_args() == ["--timeout", "3600", "--heartbeat", "20", "--heartbeat-misses", "3",
+                                 "--ack-timeout", "45"]
     seen = []
 
     def fake_run(cmd, **_kw):