Recover when the interceptor registry appears after a slow boot

[pascalbaljet]

The extension polled for window.__inertia_interceptors__ every 50 milliseconds, showed its "not running in dev mode" banner after one second, and stopped polling entirely after five. An app that boots later than that, left the panel showing that banner for the rest of the page's life even though Vite was running and the registry had appeared in the meantime.

The poll now backs off geometrically, from 50 milliseconds up to a five second beat that keeps running, so a late registry still attaches and flips the banner back off. The banner itself waits three seconds instead of one, and the console warning still fires once at the five second mark. On a page the recorder never stamped, the beat stops as soon as the document is parsed, so nothing keeps ticking where devtools was never enabled.

Fixes #3.