Supporters, Popfeed, and Donation Addresses

Supporters Integrated @ewanc26/supporters for Ko-fi webhook handling and GitHub Sponsors events. The website's /webhook endpoint accepts Ko-fi POSTs, validates the token, and appends events to the PDS. Popfeed Added a Popfeed recent reviews card to the homepage. Donations Added Monero (XMR), Bitcoin (BTC), and Ethereum (ETH) donation addresses to the footer. The footer was modularised into separate components.