Function gbnf_literal_safe 

fn gbnf_literal_safe(name: &str) -> bool

Whether name can be embedded in a GBNF double-quoted literal verbatim.

Function names are identifier-like in practice; anything that would need escaping (quotes, backslashes, control bytes, non-ASCII) makes the whole request fall back to unconstrained decode rather than risk emitting a grammar llama-server cannot compile.