fix(control-plane): forward only what the pane cannot derive - the sibling audit-log root stays on the row (Issue #57)

A worktree creator's binding always differs from its --workspace default,
so prefix() put DELEGATE_JOB_LOGS_DIR=<control root>/.mam/delegate_job_logs
into every such pane for good, and the env-first rule then kept an
experiment's --registry-dir from moving its audit log. forwarded_keys()
leaves that key out when it equals the sibling of mam_jobs_dir; a
non-sibling (explicit) root is forwarded as before. describe(), the forward
and whitespace checks and the row's four keys are unchanged.

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

.agents/skills/lib_py/control_plane.py

@@ -5,6 +5,10 @@ WORKSPACE_ROOT, AGENT_SESSIONS_YAML, MAM_JOBS_DIR, DELEGATE_JOB_LOGS_DIR.
 create/resume persist it on the row (`control_plane`) and forward it to the
 pane only when it differs from what `--workspace` alone would imply, through
 the leading `K=V` tokens lib.sh's new-session already turns into `--env`.
+The audit-log root is recorded but not forwarded when it is derivable from
+the registry (its sibling delegate_job_logs, Issue #57): in the pane the
+registry alone then decides where the audit log goes, so `--registry-dir`
+moves both.
 
 CLI (used by lib.sh):
   python -m lib_py.control_plane json <workspace> [<row control_plane JSON>]
@@ -70,10 +74,20 @@ def describe(workspace: str, row: Optional[dict] = None) -> dict:
             "whitespace": any(any(c.isspace() for c in v) for v in b.values()), "source": source}
 
 
+def forwarded_keys(desc: dict) -> list:
+    """The binding keys the pane receives: all four, minus the audit-log root
+    when it is the sibling of the registry and so derivable there (Issue #57).
+    An explicit, non-sibling root is forwarded as before."""
+    keys = list(KEYS)
+    if desc.get("delegate_job_logs_dir") == _abs(mqtt_common.sibling_logs_dir(desc["mam_jobs_dir"])):
+        keys.remove("delegate_job_logs_dir")
+    return keys
+
+
 def prefix(desc: dict) -> str:
     if not desc.get("forward"):
         return ""
-    return "".join(f"{ENV[k]}={shlex.quote(desc[k])} " for k in KEYS)
+    return "".join(f"{ENV[k]}={shlex.quote(desc[k])} " for k in forwarded_keys(desc))
 
 
 def main(argv=None) -> int: