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.

tests/mobile-test.mjs

@@ -287,6 +287,34 @@ const AXE = axeSource();
   await context.close();
 }
 
+/* 6e. reduced motion: off by default, toggled in settings -------------- */
+{
+  const { context, page } = await makePage(browser, { width: 390, height: 844 });
+  await seed(page, { decks: [DECK], theme: "aero" });
+  await page.goto(BASE, { waitUntil: "networkidle" });
+  await page.waitForTimeout(900);
+  check(
+    "motion: reduced motion is off by default",
+    !(await page.evaluate(() => document.documentElement.classList.contains("reduce-motion"))),
+  );
+  await page.locator("nav.tabbar").getByRole("button").click();
+  await page.getByRole("dialog").waitFor({ timeout: 6000 });
+  await page.waitForTimeout(500);
+  await page.getByRole("switch", { name: "Reduce motion" }).click();
+  await page.waitForTimeout(500);
+  const motion = await page.evaluate(() => ({
+    cls: document.documentElement.classList.contains("reduce-motion"),
+    bubble: getComputedStyle(document.querySelector(".ice-bubble")).animationName,
+    stored: localStorage.getItem("freezmo.reduce-motion.v1"),
+  }));
+  check(
+    "motion: the toggle parks the scene and persists",
+    motion.cls && motion.bubble === "none" && motion.stored === "1",
+    JSON.stringify(motion),
+  );
+  await context.close();
+}
+
 /* 6d. touch devices blur the real backdrop (the baked layer mispaints) - */
 {
   const { context, page } = await makePage(browser, { width: 390, height: 844, isMobile: true, hasTouch: true });