feat(cli/unstable): add promptConfirm

[crowlKats]

adds a promptConfirm function, which is similar to the built-in confirm, however provides more flexibility with letting users decide what the options are, and what the default value is.

[codecov]

Codecov Report

❌ Patch coverage is 93.05556% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 94.20%. Comparing base (1cd85bf) to head (b49a969).

Files with missing lines	Patch %	Lines
cli/unstable_prompt_confirm.ts	93.05%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6985      +/-   ##
==========================================
- Coverage   94.20%   94.20%   -0.01%     
==========================================
  Files         613      614       +1     
  Lines       47710    47782      +72     
  Branches     8299     8321      +22     
==========================================
+ Hits        44945    45011      +66     
- Misses       2697     2703       +6     
  Partials       68       68              

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[tomas-zijdemans]

Oooh, this is nice!

The trailing $ on line 120, is that intentional? I might be reading this wrong (I see your tests expect them "Continue? [y$/N$] ").

Also, maybe readLineFromStdinSync could be reused from prompt_secret.ts

[crowlKats]

regarding the $ that was a mistake on my end during experimenting that accidentally stayed in

[timreichen]

Could you add a PR description on how this differs from the built in confirm() for more clarity?

[kt3k]

Can you also add export entry in deno.json?

[kt3k]

If this is the default for values, then maybe values should be a part of the option bag? (and it also can be omitted?)

[bartlomieju]

Nice addition. A few things to address:

1. Missing export in deno.json (as @kt3k noted).
2. The default option hardcodes "n" as fallback — this is y/n-specific and doesn't work well with custom values. Consider defaulting to values[0].key instead.
3. Invalid input silently returns the default rather than re-prompting. This seems surprising — a typo would be silently accepted. Consider looping on invalid input.
4. If options.default doesn't match any value key, it silently falls back to values[0] with no error. Should validate upfront.
5. Missing @experimental tags on the exported function and types.
6. JSDoc examples reference @std/cli/unstable-confirm but the export path would be @std/cli/unstable-prompt-confirm.