Function synthesize_get_query 

pub fn synthesize_get_query<Pk>(input: &RpcGetInput<Pk>) -> Option<String>

Synthesize a URL query string from an RpcGetInput in exactly the shape the macro-generated parse_model_fetch_query parses — the direct get counterpart to synthesize_list_query, so RPC get and REST GET /<plural>/{id} run one and the same validation and projection path. Returns None when no field is set.