Function create_pr_if_needed 

pub async fn create_pr_if_needed(
    dir: &Path,
    branch: &str,
    title: &str,
    summary: &str,
    accomplished: &[String],
    remaining: &[String],
    files: &[String],
    task_id: &str,
    agent: &str,
    model: Option<&str>,
    repo: &str,
    base_branch: &str,
) -> PrCreateResult<String>

Create a PR if one doesn’t already exist.

Uses GhHttp exclusively for GitHub API operations. No gh CLI fallback is used, ensuring consistent behavior across environments.

Returns

• Ok(url) - PR URL (newly created or already existed)
• Err(PrCreateError) - API error or other failure