feat!: rewrite frontend in Vue 3 with Pinia, DaisyUI, vite-plugin-pwa

Migrates every component from class-based vue-property-decorator to
<script setup> + Composition API. Replaces Vuex 3 + vuex-class with a
single Pinia store (persisted via pinia-plugin-persistedstate). Swaps
Bulma + bulma-{checkradio,switch,pricingtable} for DaisyUI 5 utilities
on Tailwind 4. Replaces register-service-worker with vite-plugin-pwa
(workbox, skipWaiting/clientsClaim preserved).

Plugins replaced:
- vue-class-component / vue-property-decorator -> <script setup>
- vuex / vuex-class / vuex-persist -> pinia + persistedstate
- vue-i18n 8 -> vue-i18n 11 (composition mode, legacy: false)
- vue-click-outside -> @vueuse/core onClickOutside
- @xkeshi/vue-qrcode -> qrcode.vue
- vue-currency-input 1 -> vue-currency-input 3 (composable wrapper)
- bus-event (Vue instance) -> mitt
- Vue filters -> plain functions imported per component

BREAKING: drops Stripe / pricing entirely (Payment, PricingTable,
/pricing route, vue-stripe-checkout, bulma-pricingtable).

Clears unused Cypress and Jest test scaffolding; leaves a Vitest
harness behind for future tests.

src/utils/network.ts

@@ -1,20 +1,26 @@
-declare var navigator: any
+interface NetworkConnection {
+  effectiveType?: string
+  metered?: boolean
+  bandwidth?: number
+}
+
+interface NavigatorWithConnection {
+  connection?: NetworkConnection
+  mozConnection?: NetworkConnection
+  webkitConnection?: NetworkConnection
+}
 
 export const hasGoodNetwork = (): boolean => {
+  const nav = navigator as Navigator & NavigatorWithConnection
   const connection =
-    navigator.connection ||
-    navigator.mozConnection ||
-    navigator.webkitConnection
+    nav.connection || nav.mozConnection || nav.webkitConnection
 
   if (connection) {
     if (connection.effectiveType) {
-      const goodNetworks: string[] = ['3g', '4g']
+      const goodNetworks = ['3g', '4g']
       return goodNetworks.includes(connection.effectiveType)
-    } else {
-      const highBandwidth: boolean =
-        connection.metered && (connection.bandwidth || 0) > 2
-      return highBandwidth
     }
+    return !!(connection.metered && (connection.bandwidth || 0) > 2)
   }
 
   return true