fix(issue-34): the stale-review guard is armed only when the run has sub-jobs

Without --worktree/--base the guard fingerprinted the source on every
loop, so a loop whose source holds untracked files that change on every
job voided each round: test_tier4_e2e scenario 5 keeps the mock herdr's
state file (rewritten on each herdr call) in its repository and failed
with rc 1 on 3fdbb62 (passed on 7a4a0c2). A loop without sub-delegation
now behaves as before (issue #34 requirement 3); with sub-jobs the guard
protects against a deadline-closed sub-job still writing.

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

.agents/skills/lib_py/loop/runner.py

@@ -690,7 +690,7 @@ class LoopRunner:
         if reason in ORCHESTRATOR_CLOSED or (status == "error" and not reason):
             # no recorded reason is not the agent's own report either
             return "CLOSED-UNCONFIRMED", reason or "-"
-        if status == "cancelled" and (reason == "session_busy" or reason.startswith("rolled back")):
+        if status == "cancelled" and (reason in ("session_busy", "target_not_found") or reason.startswith("rolled back")):
             return "NOT-DISPATCHED", reason
         return status, reason or "-"
 
@@ -1342,15 +1342,18 @@ class LoopRunner:
                         return 1
                 else:
                     review_path = str(self.worktree_root)
-            else:
-                # Issue #34 (D9): the identity mode's B7 for every loop - a sub-job
-                # closed by deadline may still be writing to the source
+            subjobs = self._subjobs_block(self.round_roots)
+            light = None
+            if not identity and subjobs:
+                # Issue #34 (D9): the identity mode's B7, armed only when this run
+                # has sub-jobs - one closed by deadline may still be writing to the
+                # source. A loop without sub-delegation keeps its old behaviour: its
+                # source may hold untracked files that change on every job.
                 light = self._fingerprint()
                 if light is None and not guard_warned:
                     log_warn(f"cannot fingerprint the source at {self.worktree_root}; "
                              "the stale-review guard is off for this run")
                     guard_warned = True
-            subjobs = self._subjobs_block(self.round_roots)
 
             if not reviewers:
                 # Creator Self-Review