Add web app install button and step-by-step PWA guide.

src/main.ts

@@ -4,6 +4,7 @@ import 'virtual:uno.css'
 import '@unocss/reset/tailwind-compat.css'
 
 import { initPwaInstallCapture } from '@/modules/pwa/manifest'
+import { initPwaInstallPromptListener } from '@/modules/pwa/pwaInstall'
 import { initSafeAreaInsets } from '@/utils/safeAreaInsets'
 import { bootstrapApp } from '@/app/bootstrap'
 
@@ -15,4 +16,5 @@ export {
 
 initSafeAreaInsets()
 initPwaInstallCapture()
+initPwaInstallPromptListener()
 void bootstrapApp()