Unbranded version for embedding via iframe

[Aprillion]

Make a version of the UI for other websites (specifically, aisafety.com) to embed the stampy search bar from aisafety.info as an <iframe>.

Include most features but without header, footer, and the homepage default list: search bar + results + "something else" button and modal + display answer in the iframe (assuming hosting site can implement dynamic height resizing). Option to link to aisafety.info answer pages instead of showing directly in iframe is nice to have.

Make an example HTML page with <iframe>, for copy&pasting to tools that support HTML but not npm packages, like Soft (used for aisafety.com).

[Aprillion]

• [x] dark mode as url parameter (so that hosting site can control it)
• [x] embed as url parameter
• [x] remove logo, header, footer, initial list
• [x] make example iframe route
• [x] ❌ dynamic height of iframe - wasn't working reliable when using MutationObserver, so only increasing the fixed height to 100vh on focus
• [x] PR review + deploy to custom CF for testing, then merge for production deployment => https://stampy-ui.aprillion.workers.dev/embed-example.html
• [x] include on aisafety.com (in Softr preview https://aisafety.preview.softr.app/new?show-toolbar=true)

[Aprillion]

In #313, we figured out a way to set dynamic height of the iframe by sending window.parent.postMessage from the embedded page and updated https://aisafety.info/embed-example.html to demonstrate how to do it on parent page.