feat: Show loading spinner on landing page when in PWA mode (#96)

## Summary
- Prevents the landing page from briefly flashing before redirecting to
`/dashboard` when accessing from an installed PWA
- Detects standalone mode synchronously via a `useState` initializer so
the spinner renders on the very first paint
- Shows a centered loading spinner instead of the full landing page
while the redirect happens

## Test plan
- [x] Open the app as an installed PWA and verify a spinner shows
instead of the landing page before redirecting to dashboard
- [x] Open the landing page in a regular browser and verify the full
landing page renders normally with no spinner

resources/js/pages/welcome.tsx

@@ -1,6 +1,7 @@
 import EncryptionVideoPlayer from '@/components/landing/encryption-video-player';
 import Header from '@/components/partials/header';
 import { Button } from '@/components/ui/button';
+import { Spinner } from '@/components/ui/spinner';
 import {
     Tooltip,
     TooltipContent,
@@ -28,7 +29,7 @@ import {
     TrendingUpIcon,
     ZapIcon,
 } from 'lucide-react';
-import { useEffect, useRef } from 'react';
+import { useEffect, useRef, useState } from 'react';
 
 const LANDING_IMAGES = [
     {
@@ -160,13 +161,20 @@ export default function Welcome({
     const planEntries = Object.entries(pricing.plans);
     const visitTrackedRef = useRef(false);
 
-    useEffect(() => {
-        const isStandalone =
+    const [isPwa] = useState(() => {
+        if (typeof window === 'undefined') {
+            return false;
+        }
+
+        return (
             window.matchMedia('(display-mode: standalone)').matches ||
             ('standalone' in navigator &&
-                (navigator as Navigator & { standalone: boolean }).standalone);
+                (navigator as Navigator & { standalone: boolean }).standalone)
+        );
+    });
 
-        if (isStandalone) {
+    useEffect(() => {
+        if (isPwa) {
             router.visit('/dashboard');
             return;
         }
@@ -178,7 +186,15 @@ export default function Welcome({
         trackEvent(LEAD_FUNNEL_EVENT_UUID, {
             step: 'Visit',
         });
-    }, []);
+    }, [isPwa]);
+
+    if (isPwa) {
+        return (
+            <div className="flex h-screen items-center justify-center">
+                <Spinner className="size-8" />
+            </div>
+        );
+    }
 
     return (
         <>

tests/TestCase.php

@@ -29,7 +29,7 @@ abstract class TestCase extends BaseTestCase
      */
     protected function setupEncryptionKey($page, ?string $key = null, bool $reload = true): void
     {
-        $key = $key ?? $this->generateTestEncryptionKey();
+        $key ??= $this->generateTestEncryptionKey();
         try {
             $page->script("localStorage.setItem('encryption_key', ".json_encode($key).')');
         } catch (\Exception) {
@@ -39,7 +39,7 @@ abstract class TestCase extends BaseTestCase
         }
         if ($reload) {
             $currentUrl = $page->url();
-            $page->navigate($currentUrl)->wait(1);
+            $page->navigate($currentUrl)->wait(1.5);
         }
     }
 
@@ -48,7 +48,7 @@ abstract class TestCase extends BaseTestCase
      */
     protected function visitWithEncryptionKey(string $url, ?string $key = null)
     {
-        $key = $key ?? $this->generateTestEncryptionKey();
+        $key ??= $this->generateTestEncryptionKey();
         $page = visit($url);
         $page->script("localStorage.setItem('encryption_key', ".json_encode($key).')');
         $page->navigate($url)->wait(1);