GSC UI, improved app layout and beta in app agent.

## What's new

- Get GSC Insights inside the app — thanks @mattmacrocket
  - See queries in "striking distance" of ranking
- (Beta) In app agent - MCP is still recommended, but we'll be working to improve this during the summer.
  - Requires `OPENROUTER_API_KEY`
- Redesigned the app layout

## Fixed

- A wrong or mis-formatted DataForSEO API key now shows a clear message telling you how to fix it, instead of "an unexpected error occurred". — thanks @mattmacrocket
- Local business searches with invalid input now show an error instead of quietly returning nothing.
- Claude answers in AI search work again.
- Site audits no longer occasionally crash near the end of a run.

Full Changelog: https://github.com/every-app/open-seo/compare/v0.0.23...v0.0.24