Function run_loop_interactive 

pub async fn run_loop_interactive<F, Fut>(
    agent: &dyn Agent,
    tools: &ToolRegistry,
    ctx: &mut AgentContext,
    messages: &mut Vec<Message>,
    config: &LoopConfig,
    on_event: impl FnMut(LoopEvent),
    on_input: F,
) -> Result<usize, AgentError>
where
    F: FnMut(String) -> Fut,
    Fut: Future<Output = String>,

Core agent loop — single implementation for both interactive and non-interactive modes.

When a tool returns ToolOutput::waiting, calls on_input with the question. run_loop delegates here with a passive handler that returns a placeholder.