translog.append computes
sha256(canonical({prev_hash, entry_type, entry_data, timestamp})) and
writes one row per call; the first entry uses prev_hash = "0"*64.
verify_chain walks rows in id order, re-hashes each, and returns
Err("broken at id=X expected=... got=...") on the first mismatch — so
tampering with either entry_data or prev_hash invalidates every
downstream row. recent / entries_after / head support peer sync and UI.
Tests cover: genesis prev_hash, chained prev_hash, full-chain verify,
tampered-data detection, tampered-prev_hash detection, slicing.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
