Support Krea (AI image/video generation) usage tracking

[Y455B]

Problem or Motivation

Beyond coding assistants, I rely daily on Krea (krea.ai) for image and video generation. Its usage is metered too, and running out mid-session is just as disruptive as hitting a Claude or Codex limit. Right now I have to open the Krea web app to check how much I have left, which is exactly the context switch Codenotch removes for the other providers.

Proposed Solution

Add Krea as a provider showing remaining balance as a ring, like the existing credit-based providers (Kiro, DeepSeek).

Krea has two separate meters:

• Web app: compute units from the monthly subscription plan.
• API / MCP: a separate USD balance on the workspace, debited per completed generation (tracked in microdollars; requests get HTTP 402 when empty).

Caveat I'm aware of: Krea's docs currently state there is no public endpoint to read the balance programmatically ("monitor it in-app"). So this may need either:

1. an explicit sign-in in Codenotch's own WKWebView, reading the same account/usage data the Krea web app displays (the approach already used for DeepSeek and QianwenAI), or
2. waiting for Krea to expose an official balance endpoint.

Alternatives Considered

• Checking krea.ai/app/api manually — works, but defeats the purpose of a glanceable notch.
• The Custom Endpoint provider — it only probes /models health, not credits, so it can't show a balance.

Additional Context / Mockups

Docs: https://docs.krea.ai/developers/api-keys-and-billing
API pricing: https://www.krea.ai/app/api/pricing
Plans / compute units: https://www.krea.ai/pricing

Happy to test a preview build. Thanks for the app, the notch is great!