Function gitignore_walk 

pub fn gitignore_walk(
    root: &Path,
    walk_config: &WalkConfig,
) -> impl Iterator<Item = DirEntry>

Build a directory walker rooted at root, configured by WalkConfig.

• Respects ignore files as configured (default: .gitignore, .git/info/exclude, and global gitignore).
• Skips directories matching exclude patterns (default: .git).
• Visits hidden files/directories (filtering delegated to ignore files and caller).

Returns a flat iterator of successfully-read DirEntry values.