Function execute 

pub fn execute(
    execute: bool,
    agent: &str,
    project: &str,
    format: OutputFormat,
) -> Result<()>

Execute cleanup protocol: check for held resources and output cleanup guidance.

Returns Ok(()) with guidance on stdout (exit 0) for all status outcomes. ProtocolContext::collect errors propagate as anyhow::Error → exit 1.

When execute is true and status is HasResources, runs the cleanup steps via the executor instead of outputting them as guidance.