Mirror the H5a assert idiom (state invariants that already hold, no behavior change) across the split read and mutating verbs. Asserts only; wire output and exit codes unchanged.

history.zig read verbs: - decodeFullId: a validated name decodes to a whole 20/32-byte digest, never a truncated prefix. - walkLog: every checkin/phantom line renders a full valid name, and the -n cap (parseLimitValue maps 0 to null) never overruns. - stat --artifacts / timeline: the listing projects the walked rid set, is capped by -n, and the printed count matches it. - tag add: the mint targets a check-in by its full artifact id.

checkout.zig mutating verbs: - update/amend: the applied/amended target is a full artifact id. - bisect: both endpoints present before the span move. - merge: exactly one pending op (merge_parent XOR special_op) before applyMerge; revert restores only managed paths. - commit: checkout record and managed set agree before the manifest assembles; root has no pending op, merge and special exclusive, a child's parent resolved, every captured card tracked. closed check-in: 99e0c73447 user: dmestas tags: h5b-verbasserts