ADR-0075: The app watches vault_meta.data_hash, not the file's mtime

Status: accepted

Context

It is written in the same transaction as the data, so it is by construction the hash of the bytes on disk, and it is already what the compare-and-swap compares. An mtime heuristic or a Rust-side file watcher would be a second definition of "changed" to keep in step with the first

Decision

The app watches vault_meta.data_hash, not the file's mtime

Evidence

src/ts/vault-watch.ts