High-trust conformance profiledraft

What this profile is not

It is not a stricter schema. ver-record.schema.json is unchanged, and a Record that fails high-trust is still a schema-valid Record. The absence of a content_hash is a weaker claim, not a malformed document, which is exactly why it is a profile decision and not a required keyword.
It does not resolve anything over the network. No rule in either profile fetches a record_uri, and none ever will: making network reachability part of conformance is the mistake VER1303 exists to record, and the §3.5 dangling fixture is accepted for the same reason. A high-trust run of a Record whose parents are all unreachable passes, provided each parent states its content_hash.
It does not require lineage. A Record with no lineage block has no parent references, so it has nothing for VER1606 to fire on. Absence of lineage means "not stated", never "no parents" (§3.3), and this profile does not turn a silence into a claim.
It is not a trust tier. metadata.trust[] and the signature stages are untouched. This profile says one thing about one field.