fix: resolve CI test failure in output.py

- Fixed undefined 'tool' variable in display_history function
- Changed '[tool]' markup tag usage to proper Rich syntax
- All tests now pass (38/38 unit tests)
- Type checking passes with mypy --strict

tests/unit/test_llm_formatter.py

@@ -0,0 +1,112 @@
+from codesnap.output.llm_formatter import LLMFormatter
+
+
+class TestLLMFormatter:
+    def setup_method(self) -> None:
+        self.formatter = LLMFormatter(max_tokens=1000)
+
+    def test_format_valid_result(self) -> None:
+        result = {
+            "files": [
+                {
+                    "file": "test.py",
+                    "language": "python",
+                    "lines": 50,
+                    "functions": [{"name": "test_func", "start_line": 1, "end_line": 10, "parameters": [], "return_type": "str"}],
+                    "classes": [],
+                    "complexity": {"score": 5, "rating": "low"}
+                }
+            ],
+            "dependency_graph": {
+                "total_dependencies": 0,
+                "orphaned_files": 0,
+                "cycles_detected": 0,
+                "cycle_details": [],
+                "orphaned_details": [],
+                "edges": [],
+                "statistics": {}
+            }
+        }
+        output = self.formatter.format(result)
+        assert "## Codebase Summary" in output
+        assert "### Key Files" in output
+        assert "### Classes and Functions" in output
+        assert "### Dependencies" in output
+
+    def test_respects_token_limit(self) -> None:
+        result = {
+            "files": [],
+            "dependency_graph": {
+                "total_dependencies": 0,
+                "orphaned_files": 0,
+                "cycles_detected": 0,
+                "cycle_details": [],
+                "orphaned_details": [],
+                "edges": [],
+                "statistics": {}
+            }
+        }
+        output = self.formatter.format(result)
+        max_chars = 1000 * 4
+        assert len(output) <= max_chars + 100
+
+    def test_includes_high_level_summary(self) -> None:
+        result = {
+            "files": [
+                {"file": "a.py", "language": "python", "lines": 50, "functions": [], "classes": [], "complexity": {}},
+                {"file": "b.py", "language": "python", "lines": 30, "functions": [], "classes": [], "complexity": {}},
+                {"file": "c.js", "language": "javascript", "lines": 20, "functions": [], "classes": [], "complexity": {}}
+            ],
+            "dependency_graph": {
+                "total_dependencies": 0,
+                "orphaned_files": 0,
+                "cycles_detected": 0,
+                "cycle_details": [],
+                "orphaned_details": [],
+                "edges": [],
+                "statistics": {}
+            }
+        }
+        output = self.formatter.format(result)
+        assert "python" in output.lower()
+        assert "3 files" in output or "files" in output
+
+    def test_compresses_detailed_file_list(self) -> None:
+        result = {
+            "files": [
+                {"file": f"file{i}.py", "language": "python", "lines": 10,
+                 "functions": [{"name": f"func{i}a"}, {"name": f"func{i}b"}, {"name": f"func{i}c"}],
+                 "classes": [], "complexity": {}}
+                for i in range(10)
+            ],
+            "dependency_graph": {
+                "total_dependencies": 0,
+                "orphaned_files": 0,
+                "cycles_detected": 0,
+                "cycle_details": [],
+                "orphaned_details": [],
+                "edges": [],
+                "statistics": {}
+            }
+        }
+        output = self.formatter.format(result)
+        assert "Detailed File List (compressed)" in output
+
+    def test_warns_about_cycles(self) -> None:
+        result = {
+            "files": [
+                {"file": "a.py", "language": "python", "lines": 10, "functions": [], "classes": [], "complexity": {}},
+                {"file": "b.py", "language": "python", "lines": 10, "functions": [], "classes": [], "complexity": {}}
+            ],
+            "dependency_graph": {
+                "total_dependencies": 2,
+                "orphaned_files": 0,
+                "cycles_detected": 1,
+                "cycle_details": [["a.py", "b.py", "a.py"]],
+                "orphaned_details": [],
+                "edges": [],
+                "statistics": {}
+            }
+        }
+        output = self.formatter.format(result)
+        assert "circular" in output.lower() or "cycle" in output.lower()