Function fetch_issues 

pub async fn fetch_issues(
    provider: &dyn TokenProvider,
    repo_filter: Option<&str>,
    use_cache: bool,
) -> Result<Vec<(String, Vec<IssueNode>)>>

Fetches “good first issue” issues from curated repositories.

This function abstracts the credential resolution and API client creation, allowing platforms to provide credentials via TokenProvider implementations.

Arguments

• provider - Token provider for GitHub credentials
• repo_filter - Optional repository filter (case-insensitive substring match on full name or short name)
• use_cache - Whether to use cached results (if available and valid)

Returns

A vector of (repo_name, issues) tuples.

Errors

Returns an error if:

• GitHub token is not available from the provider
• GitHub API call fails
• Response parsing fails