docs: add as const to Output.choice example for proper typesafety

[max-programming]

Background

The Output.choice example in the docs did not include an as const which is useful for propert typesafety when using Output.choice. Without the as const the output is string[] and with the as const it infers that to be one of the options specified.

Summary

Added as const at the end of the options array passed to Output.choice

Before/After

Before

After

[vercel]

Additional Suggestions:

1. Missing as const in Output.choice() options arrays in documentation and examples causes incorrect TypeScript type inference (string[] instead of literal union type)

2. Missing as const in Output.choice() example in object generation documentation