fix: Remove vite-plugin-pwa, avoid this plugin caches files unexpectedly

[Copilot]

vite-plugin-pwa introduces Workbox precaching that aggressively caches frontend assets (including default icons/manifest), causing status pages to serve stale favicons instead of custom ones after the first load.

The plugin was added solely for webpush notification support, but webpush only needs a service worker that listens for push events — it doesn't need Workbox or precaching.

Changes

• public/sw.js — New static service worker with only the push notification event handler (no Workbox, no precaching)
• src/main.js — Register the service worker explicitly on app load
• config/vite.config.js — Remove VitePWA plugin
• src/serviceWorker.ts — Deleted (was only needed as vite-plugin-pwa's injectManifest input)
• package.json — Uninstall vite-plugin-pwa

Service worker (entire file)

self.addEventListener("push", function (event) {
    if (self.Notification?.permission !== "granted") {
        return;
    }
    if (event.data) {
        let message = event.data.json();
        self.registration.showNotification(message.title, { body: message.body });
    }
});

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[louislam]

The change looks solid. Need manual test.

[louislam]

Tested, it works fine.

[louislam]

Oh, wait, why it is "undefined".

[louislam]

Fixed along with this pr, I believe it is because there was no final manual test in #6421.

Let's just keep it simple, we should just use msg with Uptime Kuma as title.