- Replace old broken RegistryEntryHolderSetDecoder with correct varint
discriminator: id != 0 returns raw ID, id == 0 decodes string base
- Add RegistryEntryHolderSetEncoder using type switch (string/int32)
- Add NonErroringIndex to proto_base (zero-fallback index lookup)
- DeclareRecipes now fails with index not found (mapper) instead of to do