fix: make domain.name optional in v2 to legacy EIP-712 conversion (#283)

Some EIP-712 contracts (e.g. Safe) do not include a `name` field in
their EIP712Domain. The v2 to legacy EIP-712 converter was requiring
`domain.name` to be present and failing with "Missing domain name"
when it was absent.

Make `dapp_name` fall back to `metadata.owner` when `domain.name` is
not set, so descriptors for contracts with a minimal EIP712Domain
(e.g. only chainId + verifyingContract) can still be converted.

Made-with: Cursor

Author: lcastillo-ledger

src/erc7730/convert/ledger/eip712/convert_erc7730_v2_to_eip712.py

@@ -483,14 +483,6 @@ def _convert_resolved(
         domain = context.eip712.domain
         has_deployments = len(context.eip712.deployments) > 0
 
-        # Get dapp name from domain
-        dapp_name: str | None = domain.name if domain is not None else None
-        if dapp_name is None:
-            return out.error(
-                title="Missing domain name",
-                message="EIP-712 domain name is required for legacy EIP-712 conversion.",
-            )
-
         # Get contract name from metadata
         contract_name = descriptor.metadata.owner
         if contract_name is None:
@@ -499,6 +491,9 @@ def _convert_resolved(
                 message="metadata.owner is required for legacy EIP-712 conversion.",
             )
 
+        # Get dapp name: prefer domain.name, fall back to metadata.owner
+        dapp_name: str = (domain.name if domain is not None and domain.name is not None else None) or contract_name
+
         # Reconstruct EIP712Domain type
         domain_fields = _reconstruct_eip712_domain(domain, has_deployments, out)