Function default_tool_registry 

pub fn default_tool_registry(
    enabled: &[&str],
    cwd: &Path,
    config: &Config,
) -> ToolRegistry

Build the same ToolRegistry create_agent_session uses by default.

Useful inside a ToolFactory impl when you want to start from the standard built-in tool set and then layer custom tools on top (e.g. wrap each tool with an approval gate, or add a Task tool that spawns a nested session).