Upgrade frontend to Vue 3, Vuetify 3, and Vite

[Somainer]

• Replace Vue CLI/webpack build with Vite 5 (vite.config.ts,
  root-level index.html, vite-plugin-vuetify, vite-plugin-pwa,
  vite-plugin-monaco-editor).
• Bump core deps: Vue 2.6 -> 3.5, Vuetify 2.1 -> 3.7, Vue Router 3 -> 4,
  Vuex 3 -> Pinia 2, plus axios/socket.io-client/marked/highlight.js
  major upgrades.
• Convert main.ts, router, store.ts, and the Vuetify plugin to
  Vue 3 APIs (createApp, createRouter/createWebHistory,
  createVuetify, Pinia defineStore).
• Remove class-component ecosystem (vue-class-component,
  vue-property-decorator, vuex-class, vue-tsx-support). All
  .vue, .vue.ts, and .tsx components now use defineComponent
  and the Composition/Options API.
• Replace vue-progressbar with an nprogress-based plugin and
  vue-wechat-title with a lightweight v-page-title directive;
  drop materialize-css (BlogDigestNav/comments now use plain
  DOM/Vuetify helpers).
• Update templates for Vuetify 3 breaking changes: v-content ->
  v-main, list-item slots, variant="text/outlined" on buttons,
  icon="mdi-..." syntax, new v-data-table, v-badge
content/model-value, v-snackbar location, etc.
• Migrate lifecycle hooks (beforeDestroy/destroyed ->
  beforeUnmount/unmounted), v-model to modelValue/
  update:modelValue, slot syntax to #name/v-slot, and remove
  .native modifiers.
• Adapt RoseliaScript renderer to a local event bus so
  postUnload/postLoaded/aPlayerLoaded keep working without
  component $on/$once, and route theme/notification/goTo calls
  through Vuetify 3 composables + Pinia.
• Refresh TypeScript config for Vite (moduleResolution: bundler,
  jsxImportSource: vue) and drop Vue-2 shim typings.

https://claude.ai/code/session_01LXfFAboCUo34FtmLJiRado