Status: IN
`VersionedKVStore.put` never drops an existing version unless the new version's clock dominates it; concurrent versions are preserved as siblings.
Source: entries/2026/05/29/vector-clocks-vector_clock.md
for v in existing:
if new_vc.dominates(v.vector_clock):
pass # superseded
else:
surviving.append(v) # concurrent sibling survives
surviving.append(new_version)