test: fold the schema-retry context test into the output-schema module

Reuse tests/tools/test_delegate_output_schema.py's _StubChild instead of a
new one-test file with its own double; the invariant (the retry turn sees
is_delegated_child_context() True and the flag is restored afterwards) is
unchanged. Trim the source comment to the WHY.

tests/tools/test_delegate_output_schema.py

@@ -297,6 +297,30 @@ class TestRunSingleChildSchemaValidation:
         assert entry["status"] == "completed"
         assert "error" not in entry
 
+    def test_retry_turn_runs_in_delegated_child_context(self, monkeypatch):
+        """The retry is a second run_conversation on the child, issued from the parent's
+        thread where HERMES_KANBAN_TASK is set. Unwrapped it carries the worker's identity,
+        so the kanban stop guard nudges the child toward a board tool it does not have
+        (#109735 / #87671)."""
+        from agent.delegation_context import is_delegated_child_context
+        from tools.delegate_tool_child_run import _validate_child_output_schema
+
+        monkeypatch.setenv("HERMES_KANBAN_TASK", "t_parent")
+        seen: list = []
+
+        class _Child(_StubChild):
+            session_id = "sess-child"
+
+            def run_conversation(self, user_message, task_id=None, **_kwargs):
+                seen.append(is_delegated_child_context())
+                return super().run_conversation(user_message, task_id, **_kwargs)
+
+        child = _Child(['{"city": "Berlin"}'])
+        child._delegate_output_schema = ADDRESS_SCHEMA
+        _validate_child_output_schema(child, {"final_response": "not json", "api_calls": 1}, 0, "child-0", None)
+        assert seen == [True]
+        assert is_delegated_child_context() is False
+
 
 # ---------------------------------------------------------------------------
 # delegate_task dispatch-time schema handling

tests/tools/test_delegate_schema_retry_context.py

@@ -1,53 +0,0 @@
-"""The schema-retry turn must run inside the delegated-child context.
-
-The main child turn is wrapped in ``delegated_child_context``; the bounded retry in
-``_validate_child_output_schema`` is a second ``run_conversation`` on the same child.
-Unwrapped, it runs with the parent worker's identity: ``HERMES_KANBAN_TASK`` is set and
-nothing marks it as a child, so the kanban stop guard nudges the child to call
-``kanban_complete``. A child owns no board task and cannot, so the nudge text displaces
-the answer the retry exists to produce and the retry fails the same schema again.
-"""
-
-from __future__ import annotations
-
-import pytest
-
-from agent.delegation_context import is_delegated_child_context
-from tools.delegate_tool_child_run import _validate_child_output_schema
-
-
-class _Child:
-    """Minimal stand-in recording the context state of each run_conversation turn."""
-
-    def __init__(self):
-        self._delegate_output_schema = {
-            "type": "object",
-            "properties": {"ok": {"type": "boolean"}},
-            "required": ["ok"],
-        }
-        self.session_id = "sess-child"
-        self.seen_in_child_context = []
-
-    def run_conversation(self, user_message=None, task_id=None, stream_callback=None):
-        self.seen_in_child_context.append(is_delegated_child_context())
-        return {"final_response": '{"ok": true}', "api_calls": 1}
-
-
-@pytest.fixture
-def kanban_env(monkeypatch):
-    monkeypatch.setenv("HERMES_KANBAN_TASK", "t_parent")
-    monkeypatch.delenv("HERMES_KANBAN_STOP_NUDGE", raising=False)
-    return monkeypatch
-
-
-def test_schema_retry_runs_in_child_context(kanban_env):
-    child = _Child()
-    result = {"final_response": "not json at all", "api_calls": 1}
-
-    assert is_delegated_child_context() is False
-    _validate_child_output_schema(child, result, 0, "child-task-0", None)
-
-    assert child.seen_in_child_context == [True], (
-        "the schema-retry turn ran outside delegated_child_context"
-    )
-    assert is_delegated_child_context() is False

tools/delegate_tool_child_run.py

@@ -424,10 +424,8 @@ def _validate_child_output_schema(
     # schema re-paste — the child already holds the contract in its context).
     _retry_result = None
     try:
-        # Same identity as the main child turn (delegate_tool_child_run's worker): this runs
-        # on the parent's thread, where HERMES_KANBAN_TASK is set, so without the marker the
-        # kanban stop guard nudges the child to call kanban_complete. It owns no board task
-        # and cannot, and the nudge displaces the answer this retry exists to produce.
+        # Same identity as the main child turn: this runs on the parent worker's thread, and an
+        # unmarked turn is misread as the dispatcher-owned worker by every HERMES_KANBAN_* gate.
         from agent.delegation_context import delegated_child_context
         with delegated_child_context(str(getattr(child, "session_id", "") or "")):
             _retry_result = child.run_conversation(