Fix SPA init: poll for CDN scripts from initial load, not just observer
The MutationObserver only fires on future mutations. When the init
script loads after content swap (SPA), the content is already in the
DOM and no mutations will fire. Start polling for the CDN library
immediately from init(), not just from the observer callback.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>