Quiz embed test

Two pages standing in for Squarespace event pages, each embedding the staging quiz with a different src.

• Event A (src test-event-a)
• Event B (src test-event-b)
• Event A with ?src=test-override (the page URL wins)
• Event B with ?lang=vi (the page URL sets the language)

Quiz base URL: https://sws-quiz-staging.secretsworthsharing.workers.dev/