subscription-userinfo header

[CaiJingLong]

In Clash, the subscription has standard response headers to determine remaining traffic, total traffic, and used traffic information. However, it seems to be cleared during the subscription conversion. Therefore, can it be transmitted directly to the client?

The current prompt is

subscription-userinfo: upload=3504429949; download=117896274662; total=787213563623; expire=

The clash-verge-rev define it in https://github.com/clash-verge-rev/clash-verge-rev/blob/main/src-tauri/src/config/prfitem.rs#L64-L69

#[derive(Default, Debug, Clone, Copy, Deserialize, Serialize)]
pub struct PrfExtra {
    pub upload: u64,
    pub download: u64,
    pub total: u64,
    pub expire: u64,
}

The fields upload, download, and total are in bytes, while expire is a unit timestamp in seconds.

But actually, it just needs to pass back the response headers.