fn new(registry: HookRegistry) -> Self

fn before_tool(
        &self,
        session_id: &str,
        tool_name: &str,
        args: serde_json::Value,
    ) -> Result<HookResult>

fn after_tool(
        &self,
        session_id: &str,
        tool_name: &str,
        result: serde_json::Value,
    ) -> Result<HookResult>

fn before_agent(
        &self,
        session_id: &str,
        agent_name: &str,
        message: &str,
    ) -> Result<HookResult>

fn after_agent(
        &self,
        session_id: &str,
        agent_name: &str,
        response: &str,
    ) -> Result<HookResult>

fn on_error(&self, session_id: &str, error: &str) -> Result<HookResult>