mozilla-firefox/firefox ? reverse-engineered prompt

Build me a fast, reliable, privacy focused web browser like Firefox. I want a normal desktop browser that lets people open websites, use tabs, search or type a URL from the same bar, go back and forward, refresh pages, download files, and manage basic settings.

Please make privacy feel central, with private browsing, sensible tracking protection, clear security indicators, and no confusing dark patterns. It should feel polished and trustworthy, not like a toy demo. Include developer tools or a simple inspector if that fits naturally, since this should be useful for people building websites too.

Set up the project so I can build and run it locally, with clear instructions for contributors. Use the existing docs as the source of truth, and look up current Firefox source docs online if you need to. Keep the first pass focused on a working browser experience rather than extra bells and whistles.