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/components/CurrencyInput.vue

@@ -0,0 +1,50 @@
+<script setup lang="ts">
+import { watch } from 'vue'
+import { useCurrencyInput } from 'vue-currency-input'
+
+const props = withDefaults(
+  defineProps<{
+    modelValue: number | null
+    locale?: string
+    precision?: number
+    allowNegative?: boolean
+    valueRange?: { min?: number; max?: number }
+    placeholder?: string
+  }>(),
+  {
+    locale: 'fr-FR',
+    precision: 2,
+    allowNegative: false,
+    valueRange: () => ({ min: 0, max: 1_000_000 }),
+    placeholder: ''
+  }
+)
+
+defineEmits<{ 'update:modelValue': [value: number | null] }>()
+
+const { inputRef, setValue } = useCurrencyInput({
+  currency: undefined as unknown as string,
+  locale: props.locale,
+  precision: props.precision,
+  hideCurrencySymbolOnFocus: false,
+  hideGroupingSeparatorOnFocus: false,
+  valueRange: props.valueRange,
+  autoDecimalDigits: false
+})
+
+watch(
+  () => props.modelValue,
+  (value) => {
+    setValue(value)
+  }
+)
+</script>
+
+<template>
+  <input
+    ref="inputRef"
+    type="text"
+    class="input input-bordered w-full"
+    :placeholder="placeholder"
+  />
+</template>