Site and gallery: the repo and the showcase catalog live on Gitea at git.zacharyzhang.com

Links, the header's Gitea mark, the catalog's archive download and the showcase pin
workflow (Gitea's API and commit status) move off GitHub; pinned at 6973834, which
restores TokenLedger.

frontend/src/Shell.tsx

@@ -36,8 +36,8 @@ function Header() {
         <button className="tool" aria-label={dark ? "Light mode" : "Dark mode"} onClick={() => setMode(dark ? "light" : "dark")}>
           <Icon name={dark ? "Sun" : "Moon"} />
         </button>
-        <a className="tool" href={REPO} rel="noopener" aria-label="Ely on GitHub">
-          <Icon name="GitHub" />
+        <a className="tool" href={REPO} rel="noopener" aria-label="Ely on Gitea">
+          <Icon name="Gitea" />
         </a>
       </div>
     </header>