feat(ui): replace skeleton loaders with honest loading states

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/App.tsx

@@ -2,7 +2,7 @@ import { RouterProvider, createRouter } from '@tanstack/react-router'
 import { useEffect, useState } from 'react'
 import { routeTree } from './routeTree.gen'
 import { useAuth } from './lib/auth'
-import { Skeleton } from './components/ui/skeleton'
+import { LoadingText } from './components/ui/skeleton'
 
 const router = createRouter({
   routeTree,
@@ -24,17 +24,13 @@ function AppInner() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [])
 
-  // Only show skeleton during initial auth check -- NOT on subsequent isLoading changes.
+  // Only show loading text during initial auth check -- NOT on subsequent isLoading changes.
   // Reacting to isLoading here would unmount the entire router tree (including LoginPage)
   // every time an auth action sets isLoading, destroying all component local state.
   if (!hasChecked) {
     return (
       <div className="flex items-center justify-center min-h-screen bg-background">
-        <div className="space-y-4 w-64">
-          <Skeleton className="h-8 w-48 mx-auto" />
-          <Skeleton className="h-4 w-full" />
-          <Skeleton className="h-4 w-3/4" />
-        </div>
+        <LoadingText />
       </div>
     )
   }