Remove unconditional stateful-turn truncation

tests/test_audit.py

@@ -140,7 +140,7 @@ def test_unrecovered_major_issue_is_locally_invalid() -> None:
 
 
 @pytest.mark.parametrize("resolved", [0, -1])
-def test_non_success_outcome_is_capped_before_first_stateful_turn(resolved: int) -> None:
+def test_non_success_outcome_is_not_capped_at_first_stateful_turn(resolved: int) -> None:
     record = _record()
     record["resolved"] = resolved
     record["tools"] = [
@@ -159,9 +159,34 @@ def test_non_success_outcome_is_capped_before_first_stateful_turn(resolved: int)
     result = _boundary()
     result.update(decision="KEEP_FULL", truncate_before_turn=None)
     policy = effective_boundary_policy(record, result)
+    assert policy["decision"] == "KEEP_FULL"
+    assert policy["truncate_before_turn"] is None
+    assert policy["source"] == "MODEL_DECISION"
+    assert policy["first_stateful_turn"] == 3
+
+
+def test_semantic_boundary_is_not_replaced_by_earlier_stateful_turn() -> None:
+    record = _record()
+    record["resolved"] = 0
+    record["tools"] = [
+        {"type": "function", "function": {"name": "str_replace_editor"}}
+    ]
+    record["trajectory"][2]["tool_calls"] = [
+        {
+            "id": "call-1",
+            "type": "function",
+            "function": {
+                "name": "str_replace_editor",
+                "arguments": '{"command":"str_replace","path":"src/a.py"}',
+            },
+        }
+    ]
+    result = _boundary()
+    policy = effective_boundary_policy(record, result)
     assert policy["decision"] == "TRUNCATE"
-    assert policy["truncate_before_turn"] == 3
-    assert policy["source"] == "NON_SUCCESS_FIRST_STATEFUL_CAP"
+    assert policy["truncate_before_turn"] == 5
+    assert policy["source"] == "MODEL_BOUNDARY"
+    assert policy["first_stateful_turn"] == 3
 
 
 def test_boundary_payload_hides_outcome_and_patch_metadata() -> None: