Function handle_success 

pub async fn handle_success(
    task_id: &str,
    parsed: ParsedResponse,
    wt: &WorktreeSetup,
    task_title: &str,
    agent_name: &str,
    model_name: Option<&str>,
    new_attempts: u32,
    repo: &str,
    store: &Option<Arc<TaskStore>>,
    raw_stdout: &str,
) -> Result<(String, bool)>

Handle a successful agent response: commit, push, PR, delegations, tokens.

Returns Ok((status, push_failed)) where status is the final task status string and push_failed is true when a push was attempted but failed (for audit trail classification).