feat(issue-50): create --onboard waits for the onboarding job to end (A)

The handshake only said the agent saw the prompt (#23). create_session.sh
now waits, after `started`, for the onboarding job to reach a terminal
status and makes that its own result, so the orchestrator learns it from
create's exit (MULTI_AGENT_RULES §6) instead of guessing from herdr's
agent_status:

- lib_py/delegation/wrapper.py: `wait-terminal` (completed|error|cancelled,
  `timeout` after --timeout, `missing` when the record is gone; stops with
  its caller via --watch-pid) and `onboard-exit` (completed 0, error or
  cancelled 44, timeout or missing 45). bash branches on the printed answer.
- lib.sh: delegate_wait_terminal / delegate_onboard_exit, thin calls.
- create_session.sh: `onboarding completed: job <id> (<n>s)` on stdout, or
  `last_visible_status: onboarding-<status>` on the row, the reason on stderr
  and `exit 44` / `exit 45` after `trap - EXIT` - the session is kept, as for
  a missing handshake. The "no started" path (error, exit 0 before) now ends
  with 44. MAM_ONBOARD_WAIT_S (default 600, floor 1) bounds the wait.
- worktree_prepare.sh: 44/45 pass through with "session and worktree kept".
- create SKILL.md exit table (44, 45) and the knob; the #42 inventory follows.
- tests/conftest.py: --onboard is the default, so ~60 sandbox create tests
  reach the new wait. The mock herdr now acts as the agent for create's
  onboarding prompt - it runs the publish commands the prompt names through
  the real publish_event.py - and MAM_ONBOARD_WAIT_S=3 caps a test that turns
  that off (MAM_MOCK_ONBOARD_HANDSHAKE=0 -> 44, `started` -> 45). The
  delegate-job wrapper's prompt has another shape and is never answered.
- tests/test_issue50_onboard.py: the decision tables, create in the sandbox
  (0 / 44 / 45, session kept, row note, trap window), the knob's integer
  rule, worktree_prepare's pass-through.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tests/conftest.py

@@ -281,6 +281,12 @@ def mam_sandbox(tmp_path, monkeypatch, request):
     # Create-specific on purpose: MAM_INJECT_ACK_GRACE_S is the delegate-job
     # wrapper's knob and its own tests assert on the value they pass.
     monkeypatch.setenv("MAM_ONBOARD_ACK_S", "3")
+    # Issue #50: create now waits for the onboarding job to end as well. The
+    # mock herdr acts as the agent for create's onboarding prompt (it runs the
+    # publish commands the prompt names, through the real publish_event.py),
+    # so the wait ends at once; this cap is for a test that turns that off
+    # (MAM_MOCK_ONBOARD_HANDSHAKE=0 / started) and expects 44 / 45.
+    monkeypatch.setenv("MAM_ONBOARD_WAIT_S", "3")
     monkeypatch.delenv("HERDR_SESSION_NAME", raising=False)
     monkeypatch.delenv("HERDR_SERVER_NAME", raising=False)
     monkeypatch.delenv("HERDR_WORKSPACE_ID", raising=False)
@@ -356,6 +362,27 @@ if os.path.exists(state_file):
             pass
         time.sleep(0.02)
 
+def _onboard_handshake(text):
+    # Issue #50: create's onboarding prompt names the publish commands it
+    # expects the agent to run. This fake agent runs them - through the real
+    # publish_event.py, as a real agent would - so create's wait for the
+    # onboarding to end is satisfied. MAM_MOCK_ONBOARD_HANDSHAKE=0 publishes
+    # nothing (create exits 44: no started), `started` publishes only the
+    # first (create exits 45: never completed). The delegate-job wrapper's
+    # prompt has another shape and is never answered here.
+    import re
+    import subprocess
+    mode = os.environ.get("MAM_MOCK_ONBOARD_HANDSHAKE", "1")
+    if mode == "0" or "On start run:" not in text:
+        return
+    for label in ("On start run:", "On success run:"):
+        m = re.search(r"^" + re.escape(label) + r"\\s+(.+?)\\.?\\s*$", text, re.M)
+        if m:
+            subprocess.run(["bash", "-c", m.group(1)], stdout=subprocess.DEVNULL,
+                           stderr=subprocess.DEVNULL, timeout=120)
+        if mode == "started":
+            break
+
 # Record the command call
 state.setdefault("calls", []).append(sys.argv[1:])
 try:
@@ -659,6 +686,7 @@ elif cmd1 == "pane":
             sys.exit(1)
         pane_id = args[2]
         text = args[3]
+        _onboard_handshake(text)
         found = False
         for a_name, data in state.get("agents", {}).items():
             if data.get("pane_id") == pane_id or a_name == pane_id:
@@ -1147,6 +1175,7 @@ elif cmd1 == "agent":
         target_agent = agents[matched_k]
         target_agent["sent_text"] = target_agent.get("sent_text", "") + text
         target_agent["buffer"] = target_agent.get("buffer", "") + "\\n" + text + "\\n\\nesc to interrupt"
+        _onboard_handshake(text)
         if wait_flag:
             p_res = state.get("prompt_wait_result")
             if p_res is None: