fix(delegate): submit also takes the target workspace's update admission (Issue #72, review R1)

Decision 8: delegate submit uses the admission lock of the workspace the
target session belongs to. The wrapper resolved only its own
WORKSPACE_ROOT, so a job could be registered and delivered to an agent of
another installed workspace while that workspace was being updated.

lib_py.update target-workspace resolves a herdr:<name> row's workspace (the
.mam at or above its pane.cwd, else its control_plane.workspace_root);
mam_update_admit takes an fd, and submit holds the caller root on fd 7 and
the target on fd 8 until the record is written. Rowless and remote targets
keep the caller-root gate.

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

.agents/skills/lib.sh

@@ -3264,26 +3264,27 @@ mam_control_plane_prefix() {
 # fd 7 (`7>&-` on such a child, as pane_lock's fd 9). The wait is bounded by
 # MAM_UPDATE_ADMISSION_WAIT_S (default 120).
 #
-# mam_update_admit [workspace]: rc 0 admitted (fd 7 held, unless the workspace
-# has no .mam), 1 refused (stderr).
+# mam_update_admit [workspace [fd]]: rc 0 admitted (fd 7, or the given one,
+# held unless the workspace has no .mam), 1 refused (stderr). Delegate submit
+# also takes its target's workspace on fd 8.
 mam_update_admit() {
-  local root="${1:-$WORKSPACE_ROOT}"
+  local root="${1:-$WORKSPACE_ROOT}" fd="${2:-7}"
   local lock="$root/.mam/update-admission.lock" marker="$root/.mam/update-in-progress" st
   # No .mam: not an installed workspace, which is all the update runs in (and a
   # checkout running its own scripts gets no .mam from this).
   [ -d "$root/.mam" ] || return 0
-  if ! exec 7>>"$lock"; then
+  if ! eval "exec $fd>>\"\$lock\""; then
     echo "ERROR: cannot open the update admission lock $lock" >&2
     return 1
   fi
-  case "$(PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" python3 -m lib_py.pane_lock acquire --fd 7 --shared --wait-env MAM_UPDATE_ADMISSION_WAIT_S)" in
+  case "$(PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" python3 -m lib_py.pane_lock acquire --fd "$fd" --shared --wait-env MAM_UPDATE_ADMISSION_WAIT_S)" in
     locked) ;;
     timeout)
-      exec 7>&-
+      mam_update_admit_release "$fd"
       echo "ERROR: an update of $root holds its admission lock (MAM_UPDATE_ADMISSION_WAIT_S passed); try again when it has finished" >&2
       return 1 ;;
     *)
-      exec 7>&-
+      mam_update_admit_release "$fd"
       echo "ERROR: the update admission lock $lock could not be decided (lib_py.pane_lock)" >&2
       return 1 ;;
   esac
@@ -3296,11 +3297,11 @@ mam_update_admit() {
       echo "NOTE: stale update marker $marker (its update is gone); ignored" >&2
       return 0 ;;
   esac
-  exec 7>&-
+  mam_update_admit_release "$fd"
   echo "ERROR: an update of $root is in progress (marker $marker, holder $st); try again when it has finished" >&2
   return 1
 }
 
 mam_update_admit_release() {
-  exec 7>&-
+  eval "exec ${1:-7}>&-"
 }

.agents/skills/lib_py/update.py

@@ -16,6 +16,11 @@ this module what needs parsing. Standard library only, Python 3.9.
   python -m lib_py.update monitor --workspace W
       JSON {"pids": [...], "lock": "free"|"held"}: the monitor daemons
       daemon.find_running recognises, and whether .mam/monitor.lock is held.
+  python -m lib_py.update target-workspace --workspace W --agent-session S
+      The installed workspace a delegate target `herdr:<name>` belongs to
+      (decision 8), when it is not W: the nearest directory holding a .mam
+      at or above its row's pane.cwd, else the row's control_plane
+      workspace_root. Nothing for a rowless or non-herdr target.
   python -m lib_py.update backup-registry --workspace W --dest D
       Copies the registry into D under the registry's own write lock
       (agent-sessions.db.lock, as atomic_yaml takes it): the DB through the
@@ -231,6 +236,31 @@ def precheck(workspace: str, state: dict, herdr: str, env: Mapping[str, str]) ->
     return blockers
 
 
+# --------------------------------------------------------------------------- delegate target
+
+def target_workspace(workspace: str, state: dict, agent_session: str) -> str:
+    if not agent_session.startswith("herdr:"):
+        return ""
+    name = agent_session[len("herdr:"):]
+    row = next((s for s in state.get("herdr_sessions") or []
+                if isinstance(s, dict) and s.get("name") == name), None)
+    if row is None:
+        return ""
+    found = ""
+    cwd = (row.get("pane") or {}).get("cwd") or ""
+    d = _real(cwd) if cwd else ""
+    while d and not found:
+        if os.path.isdir(os.path.join(d, ".mam")):
+            found = d
+        elif os.path.dirname(d) == d:
+            break
+        d = os.path.dirname(d)
+    if not found:
+        root = (row.get("control_plane") or {}).get("workspace_root") or ""
+        found = _real(root) if root else ""
+    return "" if found == _real(workspace) else found
+
+
 # --------------------------------------------------------------------------- monitor
 
 def monitor_state(workspace: str) -> dict:
@@ -288,6 +318,9 @@ def main(argv: Optional[List[str]] = None) -> int:
     s.add_argument("--herdr", required=True)
     s = sub.add_parser("monitor")
     s.add_argument("--workspace", required=True)
+    s = sub.add_parser("target-workspace")
+    s.add_argument("--workspace", required=True)
+    s.add_argument("--agent-session", required=True)
     s = sub.add_parser("backup-registry")
     s.add_argument("--workspace", required=True)
     s.add_argument("--dest", required=True)
@@ -303,6 +336,13 @@ def main(argv: Optional[List[str]] = None) -> int:
         for line in lines:
             print(line)
         return 1 if lines else 0
+    if a.cmd == "target-workspace":
+        try:
+            state = _state()
+        except ValueError:
+            state = {}
+        print(target_workspace(ws, state, a.agent_session))
+        return 0
     if a.cmd == "monitor":
         print(json.dumps(monitor_state(ws)))
         return 0

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

@@ -301,10 +301,19 @@ cmd_submit() {
   local reg_dry=()
   if [[ "$DRY_RUN" == "1" ]]; then reg_dry=(--dry-run); fi
 
-  # Issue #72: no job is registered while an update of the target's workspace
-  # runs; held until the record is written (lib.sh mam_update_admit). A
-  # dry-run record is never dispatched and is not counted by the update.
-  if [[ "$DRY_RUN" != "1" ]]; then mam_update_admit "$WORKSPACE_ROOT" || exit 1; fi
+  # Issue #72: no job is registered while an update of this registry's
+  # workspace or of the target's (its row's workspace, lib_py.update
+  # target-workspace) runs; held until the record is written (lib.sh
+  # mam_update_admit). A dry-run record is never dispatched and is not
+  # counted by the update.
+  if [[ "$DRY_RUN" != "1" ]]; then
+    local target_ws
+    target_ws="$(MAM_STATE_JSON="$(load_state_json)" PYTHONPATH="$SKILL_DIR:${PYTHONPATH:-}" "$PY" -m lib_py.update \
+      target-workspace --workspace "$WORKSPACE_ROOT" --agent-session "$AGENT_SESSION")" \
+      || { echo "ERROR: cannot resolve the workspace of $AGENT_SESSION" >&2; exit 1; }
+    mam_update_admit "$WORKSPACE_ROOT" || exit 1
+    if [[ -n "$target_ws" ]]; then mam_update_admit "$target_ws" 8 || exit 1; fi
+  fi
   # 1) register job (prints the new job id)
   JOB_ID="$("$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" register \
       "${reg_prompt[@]}" --agent "$AGENT" --agent-session "$AGENT_SESSION" --role "$DELEGATE_ROLE" \
@@ -314,7 +323,7 @@ cmd_submit() {
       --job-type "$TYPE" --reviewer "$REVIEWER" --reviewer-session "$REVIEWER_SESSION" \
       --max-iterations "$MAX_ITERATIONS" ${reg_parent[@]+"${reg_parent[@]}"} ${reg_dry[@]+"${reg_dry[@]}"})"
   echo "registered job: $JOB_ID"
-  [[ "$DRY_RUN" == "1" ]] || mam_update_admit_release
+  [[ "$DRY_RUN" == "1" ]] || { mam_update_admit_release; mam_update_admit_release 8; }
 
   # 1-1) Provision job directory and write direct brief.md (MAM Job Restructuring)
   local job_dir="$REGISTRY_DIR/$JOB_ID"