everywall/ladder ? reverse-engineered prompt

Build me a self hosted web proxy app that lets me paste in any URL and view the page through my server.

I want it to load pages in a simple browser style homepage, or let me open a URL directly in the proxy path. It should also have an API endpoint and a raw HTML view. The proxy needs to be able to tweak responses, like removing or changing CORS and other headers, and optionally inject or remove small bits of HTML, CSS, or JavaScript so pages stay usable.

Please include support for a ruleset file that can apply different behavior per domain, plus the ability to limit which domains are allowed. I’d also like basic auth, custom user agent and forwarded IP settings, access logs, and a way to run it easily with Docker. If it makes sense, make the default setup work out of the box with a ruleset URL, and keep the interface simple for everyday use.