Small tweaks

I've made three small changes, all based on excellent suggestions by Fenec250:

1) Orgone multiplier is set to 0 when stamina reaches zero. This should eliminate the possibility of ignoring the stamina mechanic, as it also sets orgone gain to 0.

2) Stamina decreases both at the LLM's discretion, but also programmatically based on time elapsed. I've adjusted the formula so that this stamina loss is now proportional to not just time elapsed, but also orgone gained, so that you do not lose huge amounts of stamina just hanging out.

3) I've adjusted the sleep prompt to hopefully better acknowledge that sleep has occured in the narration.