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)/_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) {