Brand name shown as «تدریسینو ریاضی» everywhere users see it (splash, login, onboarding, footer, subscription, share); splash nowrap + balanced titles for narrow phones

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

src/screens/SplashScreen.tsx

@@ -7,7 +7,7 @@ export function SplashScreen() {
   return (
     <div className="boot-splash" dir="rtl">
       <img src="/app-icon.png" alt="" width={144} height={144} />
-      <span>تدریسینو</span>
+      <span>تدریسینو ریاضی</span>
     </div>
   );
 }