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_cli.py

@@ -0,0 +1,60 @@
+"""Unit tests for CLI module."""
+
+import os
+import tempfile
+
+from click.testing import CliRunner
+
+from codesnap.__main__ import main
+
+
+class TestCLI:
+    """Tests for CLI commands."""
+
+    def setup_method(self) -> None:
+        self.runner = CliRunner()
+
+    def test_main_help(self) -> None:
+        result = self.runner.invoke(main, ["--help"])
+        assert result.exit_code == 0
+        assert "CodeSnap" in result.output
+
+    def test_cli_version(self) -> None:
+        result = self.runner.invoke(main, ["--version"])
+        assert result.exit_code == 0
+        assert "0.1.0" in result.output
+
+    def test_cli_analyze_nonexistent_path(self) -> None:
+        result = self.runner.invoke(main, ["analyze", "/nonexistent/path"])
+        assert result.exit_code != 0
+
+    def test_cli_analyze_current_directory(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            with open(os.path.join(tmpdir, "test.py"), "w") as f:
+                f.write("def test(): pass\n")
+            result = self.runner.invoke(main, ["analyze", tmpdir])
+            assert result.exit_code == 0
+
+    def test_cli_analyze_with_output_format(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            with open(os.path.join(tmpdir, "test.py"), "w") as f:
+                f.write("def test(): pass\n")
+            result = self.runner.invoke(main, ["analyze", tmpdir, "--format", "json"])
+            assert result.exit_code == 0
+
+    def test_cli_analyze_with_max_files(self) -> None:
+        with tempfile.TemporaryDirectory() as tmpdir:
+            with open(os.path.join(tmpdir, "test.py"), "w") as f:
+                f.write("def test(): pass\n")
+            result = self.runner.invoke(main, ["analyze", tmpdir, "--max-files", "10"])
+            assert result.exit_code == 0
+
+    def test_cli_languages(self) -> None:
+        result = self.runner.invoke(main, ["languages"])
+        assert result.exit_code == 0
+        assert "python" in result.output.lower()
+
+    def test_cli_info_languages(self) -> None:
+        result = self.runner.invoke(main, ["info", "--languages"])
+        assert result.exit_code == 0
+        assert "python" in result.output.lower()