[BUG] /config dialog is completely non-functional — no setting changes persist, even within the same session

Description

The /config dialog does not persist any setting changes. Pressing Enter toggles the selected option instead of saving and closing the dialog. The only way to dismiss /config is Escape, which discards all changes.

Likely regression in v2.1.181

Two macOS user accounts on the same machine exhibit different behavior:

| Account | Version | Enter key behavior | Settings persist? |
|---------|---------|-------------------|-------------------|
| thymine | v2.1.181 | Toggles the option | No |
| davidfallah | v2.1.179 | Saves and closes dialog | Yes |

This suggests the Enter key handling in /config regressed in v2.1.180 or v2.1.181.

Steps to reproduce

1. Install Claude Code v2.1.181 (CLI, macOS)
2. Run /config
3. Navigate to any toggle (e.g., "Prompt suggestions")
4. Press Enter — the option toggles instead of saving/closing
5. The only way to close is Escape, which discards changes
6. Reopen /config — all settings are back to defaults

<img width="1200" height="1018" alt="Image" src="https://github.com/user-attachments/assets/ce837593-ca69-4b3a-aa5e-242f07fbc671" />

Expected behavior

Enter should save and close the /config dialog (as it does in v2.1.179).

Workaround

Edit ~/.claude/settings.json directly. The keys used by /config toggles are undocumented but can be found via the schema or by inspecting a working account's settings file. For example:

{
  "promptSuggestionEnabled": false
}

Environment

• Claude Code CLI, macOS (Darwin 25.5.0)
• Broken on v2.1.181, works on v2.1.179
• Same machine, different user accounts