Function record_path_for 

pub fn record_path_for(root: &Path, record: &GateRecord) -> PathBuf

2026-09-26: Where record is written: <date>-<sha><shard>.json for its hardware’s default model, or when no baseline with hardware entries resolves; otherwise <date>-<sha>-<variant slug><shard>.json. A record whose hardware has no entry counts as default when it is any hardware’s default.