Add theme toggle and update MineGeo branding

components/Shell.tsx

@@ -7,6 +7,7 @@ import { user } from "@/lib/supabase";
 import { Brand } from "./Brand";
 import { SiteNav } from "./SiteNav";
 import { ReportBugButton } from "./ReportBugButton";
+import { ThemeToggle } from "./ThemeToggle";
 export async function Header() {
   const { t } = await getI18n();
   const account = await user();
@@ -16,6 +17,7 @@ export async function Header() {
         <Brand />
         <SiteNav />
         <div className="header-actions">
+          <ThemeToggle />
           <ReportBugButton />
           <Link
             href={account ? "/dashboard" : "/log-in"}
@@ -37,6 +39,7 @@ export async function Footer() {
         <p>{t("A familiar world. A whole new perspective.")}</p>
       </div>
       <div>
+        <ThemeToggle />
         <LanguageSwitcher />
         <Link href="/downloads">{t("Tools & downloads")}</Link>
         <Link href="/leaderboard">{t("Leaderboard")}</Link>