Feature request: expose usage endpoints in the API

[atogumo]

What I'd like

It would be great if the API exposed a team's resource usage, so we can read it
programmatically. Ideally covering the same categories shown in Billing → Account
usage insights:

• Bandwidth
• Web requests
• Builds (build minutes)
• Compute — Serverless Functions and Edge Functions
• ...and the other usage metrics where applicable

Why

This data lives in the UI today, but there's no documented API for it. Exposing it
would let us build cost dashboards, usage alerts, and feed the numbers into our own
tooling.

Related: #158 .

Thanks for considering! 🙏