Smooth screen transitions: new screen waits hidden until its data arrives, no half-built flash

- Navigator stage: the next screen mounts hidden under the current one and is revealed only when its
  first data has arrived (ScreenGate held by useAsync/useGateHold), at most 450 ms; a thin top bar shows
  after 120 ms of waiting. Push slides from the left, back from the right, tabs only fade.
- Session cache (stale-while-revalidate) for screen GETs: revisited screens draw instantly.
- Home map and stats are fetched during the splash, so the first screen arrives complete.
- Entrance pop-ins (mascot, islands, lesson cards) run on first view only, not on every revisit.
- Shop status card shows placeholders instead of a wrong «نداری» while loading.
- Re-tapping the open tab scrolls to top instead of reloading; sheets close with a swipe down.
- Quiz: «۱ از ۴» instead of «۱/۴» (read as a fraction), varied praise, «N تا پشتِ هم درست»,
  growth-mindset copy after a weak round, zero-reward tiles hidden.
- Streak: a concrete next step when the streak is 0 or today is still empty.

Checked in headless Chrome against the local backend (frame captures at 150 ms and 700 ms latency,
rapid tab tapping, full quiz run). Not checked on a real phone or iOS Safari.

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

src/app/App.tsx

@@ -1,11 +1,13 @@
 import { useCallback, useEffect, useState } from 'react';
 import { AnimatePresence, MotionConfig, motion } from 'motion/react';
 import { api, ApiError, http, type Grade, type UserProfile } from '@/api';
+import type { Prefetch } from '@/state/AppData';
 import { AppShell } from '@/components/AppShell';
 import { ToastProvider } from '@/components/Toast';
 import { ErrorState } from '@/components/ui';
 import { KEYS, store } from '@/lib/storage';
 import { askStore } from '@/state/askStore';
+import { clearAsyncCache } from '@/lib/useAsync';
 import { LoginScreen } from '@/screens/LoginScreen';
 import { OnboardingScreen } from '@/screens/OnboardingScreen';
 import { SetupScreen } from '@/screens/SetupScreen';
@@ -19,7 +21,7 @@ type Flow =
   | { kind: 'onboarding' }
   | { kind: 'login' }
   | { kind: 'setup'; profile: UserProfile; grades: Grade[] }
-  | { kind: 'main'; profile: UserProfile; grades: Grade[] };
+  | { kind: 'main'; profile: UserProfile; grades: Grade[]; prefetch?: Prefetch };
 
 /** کمترین زمانِ نمایشِ اسپلش، تا صفحه چشمک نزند. */
 const SPLASH_MIN_MS = 700;
@@ -33,9 +35,11 @@ export function App() {
 
   /** پروفایل و پایه‌ها را می‌گیرد و تصمیم می‌گیرد کاربر کجا برود. */
   const enter = useCallback(async () => {
-    const [profile, grades] = await Promise.all([api.profile.get(), api.grades()]);
+    // نقشه و آمار هم‌زمان با پروفایل گرفته می‌شوند تا خانه کامل بیاید، نه اول «دارم مسیرت رو میارم» و آمارِ صفر.
+    // شکستشان ورود را نمی‌خواباند: AppData همان‌ها را دوباره می‌گیرد و خطای نقشه را روی خانه نشان می‌دهد.
+    const [profile, grades, prefetch] = await Promise.all([api.profile.get(), api.grades(), prefetchMain()]);
     await trackReferral();
-    if (profile.name && profile.gradeId) setFlow({ kind: 'main', profile, grades });
+    if (profile.name && profile.gradeId) setFlow({ kind: 'main', profile, grades, prefetch });
     else setFlow({ kind: 'setup', profile, grades });
   }, []);
 
@@ -69,6 +73,7 @@ export function App() {
     () =>
       http.onSignedOut(() => {
         askStore.clear();
+        clearAsyncCache();
         setFlow({ kind: 'login' });
       }),
     [],
@@ -122,8 +127,12 @@ export function App() {
                 <MainApp
                   profile={flow.profile}
                   grades={flow.grades}
+                  prefetch={flow.prefetch}
                   payment={launchPayment}
-                  onSignedOut={() => setFlow({ kind: 'login' })}
+                  onSignedOut={() => {
+                    clearAsyncCache();
+                    setFlow({ kind: 'login' });
+                  }}
                 />
               )}
             </motion.div>
@@ -134,6 +143,15 @@ export function App() {
   );
 }
 
+/** داده‌ی صفحه‌ی اول؛ هر کدام که نرسید null می‌ماند و AppData خودش دوباره می‌گیرد. */
+async function prefetchMain(): Promise<Prefetch> {
+  const [home, summary] = await Promise.allSettled([api.home(), api.summary()]);
+  return {
+    home: home.status === 'fulfilled' ? home.value : null,
+    summary: summary.status === 'fulfilled' ? summary.value : null,
+  };
+}
+
 /** اگر کاربر با لینکِ دعوت آمده بود و حالا وارد شده، معرفی را ثبت کن. */
 async function trackReferral() {
   const code = store.get(KEYS.referralCode);