[FEATURE] remaining subscription usage

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I need a /quota command or status line support showing remaining subscription usage.

Proposed Solution

I'd like to be able to write /quota and see remaining subscription usage

Alternative Solutions

_No response_

Priority

Critical - Blocking my work

Feature Category

CLI commands and flags

Use Case Example

_No response_

Additional Context

_No response_