Function register_recursive 

pub fn register_recursive(
    root_path: Option<&str>,
    max_depth: Option<usize>,
    force: bool,
    dry_run: bool,
    exclude_patterns: &[String],
) -> Result<()>

Recursively walk directories and register orphaned sessions for all workspaces found.

Instead of walking the entire filesystem tree (which can be extremely slow for large directory hierarchies), this function discovers all VS Code workspaces upfront and filters them by the root path prefix. This is O(workspaces) instead of O(filesystem entries), making it orders of magnitude faster for deep trees.