[Feat]: Update dotns-sdk subname issuance for the new SubnodeRecord shape and lite subnames

[sphamjoli]

Component

Registration

Priority

P1

Summary

The dotNS contracts changed how names below the top level are issued, and the dotns-sdk must be
updated anywhere it issues a subname or reads a lite (PoP) name.

Two contract-side changes drive this:

1. IDotnsRegistry.SubnodeRecord gained a persist field. When true the registry indexes the
   subnode into the owner's LabelStore; when false it writes only the ownership and resolver
   record and the caller writes the label into the store separately. Every setSubnodeOwner call
   must now supply this field.
2. A PoP lite username (alice.01) is now issued as a subname alice beneath the numeric
   container 01, not as one atomic label. Its node is
   namehash(namehash(tldNode, keccak("01")), keccak("alice")), and its ownership lives in the
   registry record, not as an ERC-721 token on the registrar.

Desired outcome: the SDK constructs the current SubnodeRecord shape, and resolves and reads
ownership of a lite name at its subname node through the registry.

Proposal

The new struct shape:

struct SubnodeRecord {
    bytes32 parentNode;
    string subLabel;
    string parentLabel;
    address owner;
    bool persist;
}

• Update every place the SDK builds a SubnodeRecord / calls setSubnodeOwner to include
  persist, choosing true or false per the caller's store-indexing need.
• For a lite name <stem>.<suffix>, split on the separator and derive the node as
  namehash(namehash(tldNode, keccak(suffix)), keccak(stem)) rather than hashing the whole label
  under the TLD.
• Read a lite name's owner from the registry (owner(node)), which resolves both a tokenised name
  and a subname, rather than from the registrar's ownerOf.

Acceptance criteria

• The SDK builds against the current SubnodeRecord (with persist) and every call site sets it.
• Subname issuance and lite-name resolution derive the subname node by splitting on the separator.
• Lite-name ownership is read from the registry, not the registrar.