fix: revert splash screen overrides, remove redundant SafeAreaProvider

expo-router 56 already calls _internal_preventAutoHideAsync() internally.
Calling preventAutoHideAsync() at module level created a second user lock
that blocked the native splash indefinitely on Android, causing a crash.
SafeAreaProvider removed as expo-router's ExpoRoot already wraps with it.
Keep SplashScreen.hideAsync() to release the splash after SecureStore reads.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/_layout.tsx

@@ -2,13 +2,10 @@ import { useEffect } from "react";
 import { Stack, router, SplashScreen } from "expo-router";
 import { StatusBar } from "expo-status-bar";
 import { GestureHandlerRootView } from "react-native-gesture-handler";
-import { SafeAreaProvider } from "react-native-safe-area-context";
 import "../global.css";
 import { Colors } from "@/constants/theme";
 import { useSettings } from "@/hooks/useSettings";
 
-SplashScreen.preventAutoHideAsync();
-
 export default function RootLayout() {
   const { settings, ready } = useSettings();
 
@@ -25,7 +22,6 @@ export default function RootLayout() {
   }, [ready, settings.onboardingDone]);
 
   return (
-    <SafeAreaProvider>
     <GestureHandlerRootView style={{ flex: 1, backgroundColor: Colors.bg }}>
       <StatusBar style="light" />
       <Stack
@@ -44,6 +40,5 @@ export default function RootLayout() {
         <Stack.Screen name="onboarding" options={{ headerShown: false }} />
       </Stack>
     </GestureHandlerRootView>
-    </SafeAreaProvider>
   );
 }