refactor(navigation): consolidate navigation with href helpers and extract push device hook

- Migrate all navigation calls from magic strings to centralized href helpers
- Extract inline device registration logic into useRegisterPushDevice hook
- Remove unused terms and privacy policy routes from profile stack
- Add hrefTradeDetail helper for trade detail navigation
- Restore routePayloadCache.stashSystemMessage for group request/invite handling
- Change desktop shell tab navigation from replace to push

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';
@@ -8,6 +8,7 @@ import type { PressableProps } from 'react-native';
 import { useAppColors, shadows } from '../../../src/theme';
 import { BREAKPOINTS } from '../../../src/hooks';
 import { useHomeTabBarVisibilityStore, useTotalUnreadCount, useHomeTabPressStore } from '../../../src/stores';
+import { hrefHome } from '../../../src/navigation/hrefs';
 
 const TAB_BAR_HEIGHT = 56;
 const TAB_BAR_FLOATING_MARGIN = 12;
@@ -28,6 +29,7 @@ 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);
@@ -35,11 +37,18 @@ export default function TabsLayout() {
 
   const isHomeStackRoute = pathname === '/home' || pathname.startsWith('/home/');
 
-  const handleHomeTabPress = useCallback(() => {
-    if (pathname === '/home') {
-      triggerHomeTabPress();
-    }
-  }, [pathname, triggerHomeTabPress]);
+  const handleHomeTabPress = useCallback(
+    (e: { preventDefault: () => void }) => {
+      if (!isHomeStackRoute) return;
+      e.preventDefault();
+      if (pathname === '/home') {
+        triggerHomeTabPress();
+      } else {
+        router.navigate(hrefHome());
+      }
+    },
+    [isHomeStackRoute, pathname, triggerHomeTabPress, router]
+  );
 
   const tabBarStyle = useMemo(() => {
     if (hideTabBar) {

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

@@ -17,8 +17,6 @@ export default function ProfileStackLayout() {
       <Stack.Screen name="blocked-users" />
       <Stack.Screen name="chat-settings" />
       <Stack.Screen name="about" />
-      <Stack.Screen name="terms" />
-      <Stack.Screen name="privacy" />
       <Stack.Screen name="verification" />
       <Stack.Screen name="data-storage" />
       <Stack.Screen name="privacy-settings" />

app/(app)/(tabs)/profile/privacy.tsx

@@ -1,5 +0,0 @@
-import { PrivacyPolicyScreen } from '../../../../src/screens/profile/PrivacyPolicyScreen';
-
-export default function PrivacyPolicyRoute() {
-  return <PrivacyPolicyScreen />;
-}

app/(app)/(tabs)/profile/terms.tsx

@@ -1,5 +0,0 @@
-import { TermsOfServiceScreen } from '../../../../src/screens/profile/TermsOfServiceScreen';
-
-export default function TermsOfServiceRoute() {
-  return <TermsOfServiceScreen />;
-}

app/(app)/_layout.tsx

@@ -1,83 +1,24 @@
-import { useEffect, useRef } from 'react';
-import { Platform } from 'react-native';
+import { useEffect } from 'react';
 import { Redirect } from 'expo-router';
 
 import { AppRouteStack } from '../../src/app-navigation/AppRouteStack';
 import { messageManager, useAuthStore } from '../../src/stores';
-import { jpushService } from '../../src/services/notification/jpushService';
-
-function getDeviceType(): 'ios' | 'android' | 'web' {
-  switch (Platform.OS) {
-    case 'ios': return 'ios';
-    case 'android': return 'android';
-    default: return 'web';
-  }
-}
-
-async function getOrCreateDeviceID(): Promise<string> {
-  try {
-    const AsyncStorage = require('@react-native-async-storage/async-storage').default;
-    const DEVICE_ID_KEY = 'withyou_device_id';
-    let deviceId = await AsyncStorage.getItem(DEVICE_ID_KEY);
-    if (deviceId) return deviceId;
-    const timestamp = Date.now().toString(36);
-    const random = Math.random().toString(36).substring(2, 8);
-    deviceId = `${Platform.OS}_${timestamp}_${random}`;
-    await AsyncStorage.setItem(DEVICE_ID_KEY, deviceId);
-    return deviceId;
-  } catch {
-    return `${Platform.OS}_${Date.now()}`;
-  }
-}
+import { useRegisterPushDevice } from '../../src/hooks';
+import { hrefAuthLogin } from '../../src/navigation/hrefs';
 
 export default function AppLayout() {
   const isAuthenticated = useAuthStore((s) => s.isAuthenticated);
   const userID = useAuthStore((s) => s.currentUser?.id);
-  const deviceRegistered = useRef(false);
 
   useEffect(() => {
     messageManager.initialize();
   }, []);
 
-  useEffect(() => {
-    if (!isAuthenticated || !userID) return;
-
-    if (!deviceRegistered.current) {
-      deviceRegistered.current = true;
-
-      if (Platform.OS === 'web') {
-        // Web: register device without push_token (JPush not available on web)
-        getOrCreateDeviceID().then((deviceId) => {
-          const { pushService } = require('../../src/services/notification/pushService');
-          pushService.registerDevice({
-            device_id: deviceId,
-            device_type: 'web',
-            device_name: 'Web Browser',
-          }).catch((err: any) => {
-            console.warn('[Push] web device register failed:', err?.message);
-          });
-        });
-      } else {
-        // Mobile: JPush handles registration internally in initialize()
-        jpushService.initialize().then((ok) => {
-          if (ok && userID) {
-            jpushService.setAliasForUser(userID);
-          }
-        });
-      }
-    }
-
-    return () => {
-      if (!isAuthenticated) {
-        deviceRegistered.current = false;
-        jpushService.cleanup();
-      }
-    };
-  }, [isAuthenticated, userID]);
+  useRegisterPushDevice(isAuthenticated, userID);
 
   if (!isAuthenticated) {
-    return <Redirect href="/login" />;
+    return <Redirect href={hrefAuthLogin()} />;
   }
 
   return <AppRouteStack />;
-}
+}

app/(app)/_layout.web.tsx

@@ -6,6 +6,7 @@ import { AppDesktopShell } from '../../src/app-navigation/AppDesktopShell';
 import { AppRouteStack } from '../../src/app-navigation/AppRouteStack';
 import { BREAKPOINTS } from '../../src/hooks';
 import { messageManager, useAuthStore } from '../../src/stores';
+import { hrefAuthLogin } from '../../src/navigation/hrefs';
 
 export default function AppLayoutWeb() {
   const { width } = useWindowDimensions();
@@ -17,7 +18,7 @@ export default function AppLayoutWeb() {
   }, []);
 
   if (!isAuthenticated) {
-    return <Redirect href="/login" />;
+    return <Redirect href={hrefAuthLogin()} />;
   }
 
   if (useDesktopShell) {