feat(option): to restrict the grammar

[grencez]

A parsing expression grammar might be possible. We'd have to track a frontier, so it's best to forbid recursion in the first position.

• feat(option): Custom sampling order #36 - Wait for sampling refactor.
• Implement.

[grencez]

Grammar restrictions should apply to individual lines of character dialogue because we impose a chatbot format, which is kinda fundamental to the project.

[grencez]

llama.cpp has grammar restrictions now. It's probably better than anything I could do initially. Will give it a look.

Need to get better sxpb parsing first so the grammar can be configured! It's in flight.