fix(delegation): the sibling rule pairs with the registry's real path (Issue #57, Mac R2)

A registry directory that is itself a symlink got two audit logs: submit
resolved --registry-dir with pwd -P and wrote next to the target, while logs
derived the sibling from the link path. sibling_logs_dir() now takes the
registry's realpath; an explicit DELEGATE_JOB_LOGS_DIR still wins.
Also: forwarded_keys() normalises both sides of its comparison, and the
design doc's status row lists the audit log next to the registry.

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

.agents/skills/lib_py/control_plane.py

@@ -79,7 +79,8 @@ def forwarded_keys(desc: dict) -> list:
     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(sibling_logs_dir(desc["mam_jobs_dir"])):
+    logs = desc.get("delegate_job_logs_dir")
+    if logs and _abs(logs) == _abs(sibling_logs_dir(desc["mam_jobs_dir"])):
         keys.remove("delegate_job_logs_dir")
     return keys