P5.1: record a refused child-result disposition as an argument error

Owner item I23: a typed refusal was being recorded as status=ok. Add one row to
_EXACT_IDENTIFIER_CODES mapping CHILD_RESULT_DISPOSITION_INVALID to the EXISTING
TOOL_ARG_ERROR code, matching the typed arms join_ledger.py already publishes for
the single form. The register is BY CODE, so this one row also covers the three
plain-string producers that never publish a typed result (the batch envelope and
per-entry rejections in join_ledger.py, the ledger-append path in
task_tree_ledger.py, and the task_tree.py schema text) and re-reads the stored
traces of every past refusal, which a producer-only cutover cannot.

CHILD_RESULT_DISPOSITION_PARTIAL deliberately stays LEGACY_WARNING: those entries
did record.

ouroboros/tools/tool_result.py is SAFETY_CRITICAL (runtime_mode_policy.py:229).
The diff in that file is exactly the one table row named by the phase; no spec,
no bucket, no producer and no classifier branch changed.

HELD, not implemented here: the STEER_REJECTED and STEER_UNCONFIRMED rows of the
same owner item wait for an owner answer on whether a refused steer touches the
task's health axis (batch #3, R3-32).

Tests: one APPROVED_DELTAS row in tests/test_tool_classification_differential.py
(the table fails both on unapproved divergence and on rows that no longer fire),
and the four text-only pins in tests/test_child_result_disposition.py now also
assert the typed code, including the partial-batch carve-out. The frozen golden
fixture is untouched: ident:CHILD_RESULT_DISPOSITION_INVALID already exists in it.

ouroboros/tools/tool_result.py

@@ -717,6 +717,7 @@ _EXACT_IDENTIFIER_CODES = MappingProxyType(
         "BROWSER_BACKLOG_RETIRED_SESSIONS": "LEGACY_UNAVAILABLE",
         "TOOL_ARG_ERROR": "TOOL_ARG_ERROR",
         "INVALID_ARG": "TOOL_ARG_ERROR",
+        "CHILD_RESULT_DISPOSITION_INVALID": "TOOL_ARG_ERROR",
         "TOOL_ERROR": "TOOL_ERROR",
         "TOOL_INTERNAL_ERROR": "TOOL_INTERNAL_ERROR",
         "EXECUTOR_UNAVAILABLE": "LEGACY_UNAVAILABLE",

tests/test_child_result_disposition.py

@@ -16,6 +16,17 @@ def _parent_ctx(tmp_path, task_id: str = "parent1") -> SimpleNamespace:
     )
 
 
+def _typed_code(text: str) -> str:
+    """The code the one classifier assigns to a refusal sentence (owner item I23).
+
+    The plain-string producers below never publish a typed result, so the
+    identifier table is what decides whether a refused disposition is recorded as
+    an argument error or as a success."""
+    from ouroboros.tools.tool_result import LegacyTextResultAdapter
+
+    return LegacyTextResultAdapter.from_text("tree_note", text).code
+
+
 def _payload(child_id: str, disposition: str, result_sha256: str) -> dict:
     return {
         "type": "child_result_disposition",
@@ -236,6 +247,7 @@ def test_malformed_disposition_names_every_violation_in_one_reply(tmp_path):
     result = _tree_note(_parent_ctx(tmp_path), "decision", "x" * 501, payload=bad)
 
     assert result.count("CHILD_RESULT_DISPOSITION_INVALID") == 1
+    assert _typed_code(result) == "TOOL_ARG_ERROR"
     for fragment in (
         "unknown key(s) supports_claims",
         "disposition must be one of",
@@ -281,6 +293,7 @@ def test_ledger_append_renders_the_same_aggregated_violations(tmp_path):
     )
 
     assert out.startswith("⚠️ CHILD_RESULT_DISPOSITION_INVALID:")
+    assert _typed_code(out) == "TOOL_ARG_ERROR"
     for fragment in (
         "unknown key(s) supports_claims",
         "disposition must be one of",
@@ -394,6 +407,8 @@ def test_batch_disposition_rejects_invalid_entries_individually(tmp_path):
     assert "[stranger9] ⚠️ CHILD_RESULT_LINEAGE_FORBIDDEN" in result
     assert "disposition must be one of" in result
     assert "[entry 4] ⚠️ CHILD_RESULT_DISPOSITION_INVALID: entry must be a JSON object." in result
+    # A partial batch stays a warning: the recorded entries are real work.
+    assert _typed_code(result) == "LEGACY_WARNING"
     rows = tree_ledger_rows("parent1", data_root=tmp_path)
     assert [row["payload"]["child_task_id"] for row in rows] == ["child1"]
 
@@ -413,6 +428,7 @@ def test_batch_disposition_envelope_is_validated_atomically(tmp_path):
         result = _tree_note(_parent_ctx(tmp_path), "decision", "why", payload=payload)
         assert "CHILD_RESULT_DISPOSITION_INVALID" in result
         assert "atomic no-op" in result
+        assert _typed_code(result) == "TOOL_ARG_ERROR"
     wrong_kind = _tree_note(
         _parent_ctx(tmp_path),
         "note",

tests/test_tool_classification_differential.py

@@ -259,6 +259,14 @@ APPROVED_DELTAS: Mapping[str, Delta] = MappingProxyType({
     "native:LEGACY_UNAVAILABLE:CHILD_RESULT_STALE": Delta(False, "ok", True, "unavailable", "A.B7", "join_ledger has no current child result to bind, unlike a changed result's policy denial"),
     "native:LEGACY_UNAVAILABLE:TASK_NOT_FOUND": Delta(False, "ok", True, "unavailable", "A.B7", "forward_to_worker has no registered target for this task id"),
     "native:TOOL_ARG_ERROR:CHILD_RESULT_DISPOSITION_INVALID": Delta(False, "ok", True, "argument_error", "A.B7", "join_ledger rejects malformed disposition arguments before recording them"),
+    # Owner item I23: a typed refusal must be recorded as a refusal, not as ok.
+    # The single form already publishes the typed argument error above; the batch
+    # envelope, the per-entry rejections and the ledger-append path return the
+    # same sentence as a PLAIN STRING, so only the identifier table reaches them
+    # (and the stored traces of every past refusal). The register is BY CODE, so
+    # one row covers all four producers. CHILD_RESULT_DISPOSITION_PARTIAL keeps
+    # its warning: those entries did record.
+    "CHILD_RESULT_DISPOSITION_INVALID": Delta(False, "ok", True, "argument_error", "A.I23", "a disposition the ledger refused to record is an argument error, not a success"),
     "native:TOOL_ARG_ERROR:ERROR": Delta(False, "ok", True, "argument_error", "A.B7", "both commit entry points reject an empty commit message before attempting a commit"),
     "native:TOOL_ARG_ERROR:REJECTED": Delta(False, "ok", True, "argument_error", "A.B7", "scratchpad and identity writers reject empty or malformed content before writing"),
     "native:TOOL_ERROR:TASK_MESSAGE_UNWRITTEN": Delta(False, "ok", True, "error", "A.B7", "forward_to_worker failed to persist the requested message"),