Function hash_and_parse_parallel 

pub fn hash_and_parse_parallel(
    files: &[WalkedFile],
    stored_mtimes: &HashMap<String, u64>,
) -> HashParseOutput

Combined mtime-check + parse pass.

For each file:

• If mtime_secs matches the stored value → skip entirely (zero disk I/O).
• Otherwise → read file bytes, run tree-sitter, record updated mtime.

This eliminates the full I/O sweep on re-init when files are unchanged: a re-init with no edits costs only the walk + mtime comparison (≈130ms), not a full disk read of all source files (≈2100ms on 58k-file repos).