Update GEMINI.md with Vim folding mandate and add test cases for set-flag-format CLI command

tests/test_forensics.py

@@ -295,3 +295,29 @@ def test_forensics_flag_detect_cli_not_found():
     result = runner.invoke(forensics_group, ["flag-detect", str(test_file)])
     assert result.exit_code == 0
     assert "No flag patterns found" in result.output
+
+def test_set_flag_format_cli():
+    """
+    Verifies that 'set-flag-format' CLI command writes the pattern to config.toml.
+    """
+    from ctf.commands import set_flag_format
+    from ctf.utils import load_config
+    
+    runner = CliRunner()
+    config_file = Path("/home/venus/code/ctf/config.toml")
+    
+    # Save the original config to restore later
+    original_config = load_config(str(config_file))
+    
+    try:
+        result = runner.invoke(set_flag_format, ["TEST_FLAG{[a-z]+}"])
+        assert result.exit_code == 0
+        assert "Flag format set to" in result.output
+        
+        # Verify it was written to config.toml
+        updated_config = load_config(str(config_file))
+        assert updated_config["Competition"]["flag_format"] == "TEST_FLAG{[a-z]+}"
+    finally:
+        # Restore original config
+        from ctf.utils import write_config
+        write_config(original_config, str(config_file))