Make account name optional in API response and map nil/empty values to
"Anonymous" at the network boundary. This ensures users who haven't set
their name can remain anonymous while keeping the name non-optional in
domain and UI layers.
- Make AccountInformationResponse.Response.name optional (String?)
- Add mapping logic in AccountUpdateNetworkService to default nil/empty
names to "Anonymous"
- Preserve non-optional String type in AccountResponse and
Account models
- No changes required in UI or persistence layers
