Design pass (all themes + chat UI), model picker, reduce-motion toggle

- Aero: blue gradients back on the active segment and every primary
  (Review due, the card's Study button, the composer's send button); a
  frosted backing behind the page heading and the All decks label; a
  bottom-weighted rail tint; chat header/composer/welcome panels; calmer
  orbs; stronger card veil + a stronger blur bake.
- Dark/Light: a dedicated --track token makes progress bars read (the
  first attempt shifted --surface-sunken and the pixel scan caught the
  sheet-contrast regression); brighter dark secondary text; darker light
  segmented labels and difficulty tints; stronger light card border and
  shadow.
- Chat UI: friendly model chip ("Gemma 4 31B") with the raw name in a
  tooltip, larger chips, plain centered disclaimer, vertically centered
  welcome panel, distinct chat-plus icon for new chat.
- Chat models: every chat-capable model from the server's /api/tags is
  selectable (favourites first, search field when long, live-list
  validation in the route); default CHAT_MODEL_DEFAULT or gemma4:31b.
- Reduce motion: Settings toggle (default off) that parks the scene,
  collapses CSS animations and drives framer-motion's calm mode.
- Folders hint, "New" badge on fresh decks.

Contrast: 0 findings, axe clean, mobile 126/126, chat 102/102, wizard
95/95, regression 44/44, i18n 13/13, native 33/33.
Version 0.4.6, SW -> freezmo-v71.

components/AiDisclaimer.tsx

@@ -12,11 +12,13 @@ import { cn } from "@/lib/utils";
  * --text-subtle is the muted helper token and is documented at 5.6:1 (light)
  * and 8.6:1 (dark), so the note stays readable at this size.
  */
-export function AiDisclaimer({ className }: { className?: string }) {
+export function AiDisclaimer({ className, plain = false }: { className?: string; plain?: boolean }) {
   const { t } = useI18n();
   return (
     // hint-line: Aero gives this its own glass chip (it sits on the wallpaper).
-    <p className={cn("hint-line text-center text-[11.5px] leading-snug text-[var(--text-subtle)]", className)}>
+    // Where the note already sits on a glass panel (the chat composer), `plain`
+    // keeps it plain centered text like the other themes.
+    <p className={cn(!plain && "hint-line", "text-center text-[11.5px] leading-snug text-[var(--text-subtle)]", className)}>
       {t("common.aiDisclaimer")}
     </p>
   );