fix: classify landed file mutations with diagnostics

tests/agent/test_display.py

@@ -1,6 +1,7 @@
 """Tests for agent/display.py — build_tool_preview() and inline diff previews."""
 
 import os
+import json
 import pytest
 from unittest.mock import MagicMock, patch
 
@@ -149,6 +150,27 @@ class TestCuteToolMessagePreviewLength:
         assert path in line
         assert "..." not in line
 
+    def test_write_file_lint_error_result_is_not_marked_failed(self):
+        result = json.dumps({
+            "bytes_written": 12,
+            "lint": {"status": "error", "output": "SyntaxError: invalid syntax"},
+        })
+
+        line = get_cute_tool_message("write_file", {"path": "/tmp/a.py"}, 0.1, result=result)
+
+        assert "[error]" not in line
+
+    def test_patch_lsp_diagnostics_result_is_not_marked_failed(self):
+        result = json.dumps({
+            "success": True,
+            "diff": "--- a/tmp.py\n+++ b/tmp.py\n",
+            "lsp_diagnostics": "<diagnostics>ERROR [1:1] type mismatch</diagnostics>",
+        })
+
+        line = get_cute_tool_message("patch", {"path": "/tmp/a.py"}, 0.1, result=result)
+
+        assert "[error]" not in line
+
 
 class TestEditDiffPreview:
     def test_extract_edit_diff_for_patch(self):