style(pwa-install-dialog): redesign dialog to match Dart spec

Update the PWA install dialog styling and content to align with the
original Dart design, including a white background with large 40px
radius, 86x86 PNG icon, gradient primary button, and dynamic app title
sourced from AppConstants.

src/app/splash/components/splash-logo.tsx

@@ -1,11 +1,3 @@
-/**
- * Splash Logo
- *
- * 原始 Dart: lib/ui/splash/widgets/splash_logo.dart
- * 资源: /public/images/splash/ic-logo-home.png (kebab-case 重命名后)
- *       原名: ic_logo_home.png (snake_case)
- * 渲染: Assets.images.icLogoHome.image() → next/image <Image>
- */
 import Image from "next/image";
 import styles from "./splash-logo.module.css";
 
@@ -15,8 +7,8 @@ export function SplashLogo() {
       <Image
         src="/images/splash/ic-logo-home.png"
         alt="cozsweet"
-        width={120}
-        height={40}
+        width={180}
+        height={60}
         priority
         className={styles.image}
       />