feat(ui): improve navigation, component props, and chat logic

- update `app.json` with splash screen configuration
- implement tab navigation redirection in `TabsLayout` for apps and profile tabs
- update `HighlightText` prop usage from `style` to `highlightStyle` in `PostCard` and `PostContentRenderer`
- fix chat message segment construction to avoid empty text segments when sending only images
- refine UI styling by removing unnecessary shadows and adjusting `UserScreen` header visibility
- improve `HomeScreen` scroll behavior by disabling animation on FlashList scroll-to-top

app/(app)/(tabs)/_layout.tsx

@@ -1,6 +1,6 @@
 import { useMemo, useCallback } from 'react';
 import { Platform, Pressable, useWindowDimensions } from 'react-native';
-import { Tabs, usePathname } from 'expo-router';
+import { Tabs, usePathname, useRouter } from 'expo-router';
 import { MaterialCommunityIcons } from '@expo/vector-icons';
 import { useSafeAreaInsets } from 'react-native-safe-area-context';
 import type { PressableProps } from 'react-native';
@@ -28,6 +28,7 @@ export default function TabsLayout() {
   const { width } = useWindowDimensions();
   const insets = useSafeAreaInsets();
   const pathname = usePathname();
+  const router = useRouter();
   const unreadCount = useTotalUnreadCount();
   const scrollHideTabBar = useHomeTabBarVisibilityStore((s) => s.bottomTabBarHiddenByScroll);
   const triggerHomeTabPress = useHomeTabPressStore((s) => s.triggerPress);
@@ -41,6 +42,18 @@ export default function TabsLayout() {
     }
   }, [pathname, triggerHomeTabPress]);
 
+  const handleAppsTabPress = useCallback(() => {
+    if (pathname.startsWith('/apps/')) {
+      router.replace('/apps');
+    }
+  }, [pathname, router]);
+
+  const handleProfileTabPress = useCallback(() => {
+    if (pathname.startsWith('/profile/')) {
+      router.replace('/profile');
+    }
+  }, [pathname, router]);
+
   const tabBarStyle = useMemo(() => {
     if (hideTabBar) {
       return { display: 'none' as const, height: 0, overflow: 'hidden' as const };
@@ -116,6 +129,9 @@ export default function TabsLayout() {
             />
           ),
         }}
+        listeners={{
+          tabPress: handleAppsTabPress,
+        }}
       />
       <Tabs.Screen
         name="messages"
@@ -143,6 +159,9 @@ export default function TabsLayout() {
             />
           ),
         }}
+        listeners={{
+          tabPress: handleProfileTabPress,
+        }}
       />
     </Tabs>
   );