Centralize remaining prompts into prompts.ts

[nanodeath]

Many prompts are in prompts.ts but there are also others scattered around, like in agents.ts and moderator.ts.

While I'm not 100% sold on putting all the prompts in one .ts file (violates SOLID?), we should at least be consistent, and for now I'd rather pull everything into prompts.ts rather than delete prompts.ts and distribute the prompts. Might change my mind later though.