Add confirmation prompt before sending `/extra-usage` request

Description

The /extra-usage command immediately sends a request to the organization admin without any confirmation prompt. This can lead to accidental requests being sent with no way to cancel them.

Current Behavior

1. User types /extra-usage
2. Request is immediately sent to the admin
3. Output: Request sent to your admin to enable extra usage.

There is no confirmation step and no way to cancel the request once sent.

Expected Behavior

A confirmation prompt should be shown before sending the request:

This will send a request to your organization admin to enable extra usage. Proceed? [y/N]

Only after the user confirms (e.g., typing y) should the request actually be sent.

Why This Matters

• Accidental requests: Users may trigger the command unintentionally (e.g., exploring available commands, typos) and end up sending a request to their admin.
• No undo: Once the request is sent, there is no built-in way to cancel it. The user must manually contact their admin to ask them to ignore it.
• Consistency: Other potentially impactful CLI actions typically include a confirmation step before proceeding.

Suggested Solution

Add a simple y/N confirmation prompt before the request is dispatched, defaulting to "No" to prevent accidental sends.