fix(ui): kiosk dropdown flash + never inherit the OS light theme

Outside-close listeners move from click to pointerdown: pointerdown
fires before the open-toggle re-render, so the kiosk's slow software
compositing can no longer detach the click target mid-flight and close
the menu the instant it opens. color-scheme:dark (CSS + meta) pins every
native control — select popups, scrollbars, pickers — dark regardless of
the user's OS theme; explicit select/option colors cover Firefox.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/index.html

@@ -14,6 +14,8 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover, interactive-widget=resizes-content" />
     <meta name="description" content="Archipelago - Your sovereign personal server" />
     <meta name="theme-color" content="#000000" />
+    <!-- Dark-only app: pin native controls dark before CSS loads. -->
+    <meta name="color-scheme" content="dark" />
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-capable" content="yes" />
     <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />