bug(cli): cleanup double-prompts — confirming 'delete all' still requires a second per-version 'y', silently skips if missed

[dipto0321]

Describe the bug

Confirming deletion at the post-upgrade cleanup's all-or-nothing prompt ("What would you like to do? y / / N") does not actually delete anything on its own — a second, separate per-version confirmation is silently required afterward, and if it's missed, every candidate is skipped with no visible error and fnm uninstall/m.Uninstall() never runs.

Root cause

internal/cli/cleanup.go:

1. promptAllOrNothing (called at runCleanupPrompt Step 3, line ~133) correctly parses a y answer as decision.deleteAll = true, setting toOffer = candidates (line 156).
2. Step 4 (line 164-187) then unconditionally loops over toOffer and, because cfg.PerVersion defaults to true (from cleanup.prompt: true's config default), calls promptPerVersion(v, streams) again for every single version — regardless of the "delete all" answer already given in Step 3.
3. Nothing sets cfg.PerVersion = false after decision.deleteAll is chosen. So the user is asked to confirm twice: once for "delete all," then once more per individual version.
4. If that second round of prompts doesn't receive an explicit y for each version (e.g., the user only meant to answer once, or the terminal session's input ends there), promptPerVersion defaults to "no" (cleanup.go:326-331, the default: case), each version lands in result.Skipped, and m.Uninstall(v) is never called.

Reproduction

nodeup upgrade
# at the "Old Node.js versions still on disk (N): ... What would you like to do?" prompt, answer: y

Expected: all listed old versions get deleted (the user just explicitly said "delete all").
Actual: a second, separate Delete v<x>? [y/N] prompt appears per version; if not answered y again for each one, the versions are silently kept, with no clear indication that the first "y" wasn't sufficient.

User-reported symptom

Confirmed live: user answered y/a version number at the cleanup prompt during a real nodeup upgrade, but fnm list afterward still showed the old versions — no deletion occurred.

Suggested fix (not applied — filing only per request)

When decision.deleteAll (or a specific decision.deleteOne) is chosen at the all-or-nothing prompt, that should be treated as sufficient confirmation — either skip the per-version loop's confirmation entirely for those already-confirmed candidates (set cfg.PerVersion = false for this call once a deleteAll/deleteOne decision is made), or make it unambiguous to the user that a second per-version confirmation is coming.

Severity

High — this is the core promise of the cleanup feature (deleting confirmed old versions) silently not happening despite explicit user confirmation, with no error surfaced.