lighter first load, math reads left-to-right in quizzes, tickets from the server, readable separators

- Every screen but home is its own chunk and preloads when the browser is
  idle; React and motion get their own long-cached chunks. The app entry
  goes from 505 kB (160 kB gzip) to 85 kB (27 kB gzip).
- Quiz prompts, options and lesson examples go through MathText, so
  '10 + 3 - 7 - 2' reads from the left; an unpaired bracket at the edge of
  a math run stays with the Persian sentence.
- Support lists tickets from GET /support/tickets instead of this
  browser's localStorage; a ticket's messages load when it is opened.
- '·' next to a Persian zero read as another digit ('فصلِ ۱ · ۰' looked
  like ۱۰۰); a thin bar separates them now. Notification bodies show
  Persian digits.
- A root or vertex the model already marked with coordinates is no longer
  labelled a second time on top of it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/components/ui.tsx

@@ -154,6 +154,14 @@ export function EmptyState({ text, char = 'pi' as SeyarChar }: { text: string; c
   return <StateBox char={char} mood="idle" text={text} />;
 }
 
+/**
+ * جداکننده‌ی میانِ دو تکه‌ی متن. «·» کنارِ صفرِ فارسی (که خودش یک نقطه است)
+ * خوانده نمی‌شد: «فصلِ ۱ · ۰ از ۴» شبیهِ «۱۰۰» دیده می‌شد.
+ */
+export function Sep() {
+  return <span aria-hidden className="mx-1.5 inline-block h-2.5 w-px bg-current align-middle opacity-40" />;
+}
+
 export function InlineError({ children }: { children: ReactNode }) {
   return (
     <div role="alert" className="rounded-xl border border-red-200 bg-red-50 px-3 py-2.5 text-xs leading-6 text-red-600">