fix(issue-50): the loop path waits by the registry on its pending record (review F1-F3)

F1: from phase two on, the loop's `_registry_wait` ran before the record was
reset to pending, so the waiter held a terminal record: the engine refused its
dispatch_wait_at merge and other waiters never saw it in the FIFO. The wait
(and the idle wait after it) now follows the `--status pending` update; s1
pins the order and u3c shows why a terminal self record cannot signal.
F2: the real-herdr box teardown survives a hung stop/delete, kills a server
bootstrapped by a late client call, and asserts the server and HOME are gone.
F3: the delegate-job SKILL.md exit 5 row names the registry wait.
Also drops the dead loop in s1.

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

.agents/skills/multi-agent-mux-delegate-job/SKILL.md

@@ -104,7 +104,7 @@ Under fail-closed operation (`MAM_DELEGATE_FAIL_CLOSED=1`, default), the CLI ret
 | `2` | Timeout | `error` (`deadline_timeout`) | Subscriber idle timeout (K x N without an event; the total budget is the wall-clock row below). **R1 liveness grace (Issue #18)**: after the subscriber idles out the wrapper keeps re-observing the disk while the job's events.log shows an event at most K x N (`--idle-timeout`) old - the automatic heartbeat counts - up to the wall-clock `--timeout`. herdr status and the pane are logged as a diagnostic only. |
 | `2` | Wall clock | `error` (`wall_clock_timeout`) | The budget (`--timeout`) ran out, events or not (Issue #33; was `deadline_timeout` before v4.8.0). |
 | `3` | Broker Error | `error` (`wall_clock_timeout` once the budget is spent, else `deadline_timeout`) | Broker unavailable (`MQTT_BROKER_UNAVAILABLE`) and terminal status not found on disk during deadline. |
-| `5` | Session Busy | `cancelled` (`session_busy`) | Precondition failed / `session_busy`: Preflight check (`preflight_agent`) or TUI idle handshake wait failed (prompt never delivered, retryable). |
+| `5` | Session Busy | `cancelled` (`session_busy`) | Precondition failed / `session_busy`: Preflight check (`preflight_agent`) or TUI idle handshake wait failed, or the session's open jobs in the registry did not end within `MAM_DISPATCH_WAIT_S` (Issue #50) (prompt never delivered, retryable). |
 
 In all execution paths, the final line of standard output prints the persistent audit log directory path (`<logs_root>/<job_id>`), fulfilling the parsing contract for orchestrator runners.
 

.agents/skills/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -518,7 +518,19 @@ EOF
         exit 5
       fi
 
-      # Registry wait (Issue #50), then idle wait
+      # Update job details in registry
+      "$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" update \
+          --job "$JOB_ID" \
+          --agent-session "$current_session" \
+          --prompt-file "$job_dir/prompt.md" \
+          --iteration "$iteration" \
+          --attempt-id "$attempt" \
+          --role "$display_role" \
+          --status "pending"
+
+      # Registry wait (Issue #50), then idle wait - on the record just reset to
+      # pending for this phase, so the waiter's signal is written and other
+      # waiters see this job in the FIFO (review F1)
       local cur_agent="$AGENT"
       [ "$_phase" = "reviewer" ] && cur_agent="$REVIEWER"
       if [ "$cur_agent" != "human" ] && ! _is_remote "$current_session"; then
@@ -534,16 +546,6 @@ EOF
         fi
       fi
 
-      # Update job details in registry
-      "$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" update \
-          --job "$JOB_ID" \
-          --agent-session "$current_session" \
-          --prompt-file "$job_dir/prompt.md" \
-          --iteration "$iteration" \
-          --attempt-id "$attempt" \
-          --role "$display_role" \
-          --status "pending"
-
       local _disp_tok=""
       _disp_tok="$("$PY" -c "import json, os; p=os.path.join('$REGISTRY_DIR', '$JOB_ID.json'); print(json.load(open(p)).get('dispatch_token','') or '') if os.path.exists(p) else print('')" 2>/dev/null || true)"