Expose instructions getter in realtime session?

[willsmanley]

I have a pattern where I update system prompt / instructions dynamically during the course of a conversation with realtime agent.

I'd like to do a simple check to compare updated instructions with existing instructions, however its private behind _opts.

Since instructions is initially a consumer-facing property during initialization, maybe it should be accessible afterwards with a public getter?

This is a pretty minor thing, I can always have a duplicate copy on my application side, but it adds some duplicative memory footprint when the prompt is particularly long.

However could be a simple change in realtime.py like this:

class RealtimeSession(utils.EventEmitter[EventTypes]):
    @property
    def instructions(self) -> str:
        return self._opts.instructions

Sorry for bug label, it won't let me create an issue any other way.