[Feature] Smart Routing Based on Account Usage

### Version

v0.260716.1

### OS & Architecture

Linux x86_64

### Category

Other

### Scenario

We shared Codex Pro Plan Credits on Tingly Box, Some of us are using their own account directly so their accounts usage ran out faster than others. It's nice to have a new rule that route will prefer to use account who has more usage left.

### Proposed Solution

_No response_