feat(i18n): add PuroLocaleSwitcher for portal pages

frontend/src/components/puro/PuroLocaleSwitcher.vue

@@ -0,0 +1,150 @@
+<template>
+  <div class="puro-locale" ref="dropdownRef">
+    <button
+      class="puro-locale-btn"
+      type="button"
+      :disabled="switching"
+      :aria-expanded="isOpen"
+      :title="currentLocale?.name"
+      @click="toggleDropdown"
+    >
+      <span class="puro-locale-code">{{ currentLocale?.code.toUpperCase() }}</span>
+      <svg class="puro-locale-chev" :class="{ open: isOpen }" viewBox="0 0 12 12" width="10" height="10" aria-hidden="true">
+        <path d="M2 4l4 4 4-4" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round"/>
+      </svg>
+    </button>
+
+    <transition name="puro-locale-pop">
+      <div v-if="isOpen" class="puro-locale-menu" role="listbox">
+        <button
+          v-for="option in availableLocales"
+          :key="option.code"
+          type="button"
+          role="option"
+          :aria-selected="option.code === currentLocaleCode"
+          class="puro-locale-option"
+          :class="{ active: option.code === currentLocaleCode }"
+          :disabled="switching"
+          @click="selectLocale(option.code)"
+        >
+          <span class="puro-locale-option-code">{{ option.code.toUpperCase() }}</span>
+          <span class="puro-locale-option-name">{{ option.name }}</span>
+          <span v-if="option.code === currentLocaleCode" class="puro-locale-option-dot" aria-hidden="true"></span>
+        </button>
+      </div>
+    </transition>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, computed, onMounted, onBeforeUnmount } from 'vue'
+import { useI18n } from 'vue-i18n'
+import { setLocale, availableLocales } from '@/i18n'
+
+const { locale } = useI18n()
+const isOpen = ref(false)
+const dropdownRef = ref<HTMLElement | null>(null)
+const switching = ref(false)
+
+const currentLocaleCode = computed(() => locale.value)
+const currentLocale = computed(() => availableLocales.find((l) => l.code === locale.value))
+
+function toggleDropdown() {
+  isOpen.value = !isOpen.value
+}
+
+async function selectLocale(code: string) {
+  if (switching.value || code === currentLocaleCode.value) {
+    isOpen.value = false
+    return
+  }
+  switching.value = true
+  try {
+    await setLocale(code)
+    isOpen.value = false
+  } finally {
+    switching.value = false
+  }
+}
+
+function handleClickOutside(event: MouseEvent) {
+  if (dropdownRef.value && !dropdownRef.value.contains(event.target as Node)) {
+    isOpen.value = false
+  }
+}
+
+onMounted(() => document.addEventListener('click', handleClickOutside))
+onBeforeUnmount(() => document.removeEventListener('click', handleClickOutside))
+</script>
+
+<style scoped>
+.puro-locale { position: relative; display: inline-flex; }
+
+.puro-locale-btn {
+  display: inline-flex; align-items: center; gap: 6px;
+  padding: 6px 10px;
+  font-family: var(--font-mono, ui-monospace, SFMono-Regular, Menlo, monospace);
+  font-size: 12px; font-weight: 500;
+  color: var(--text-1, #cbd5e1);
+  background: rgba(2, 6, 23, 0.4);
+  border: 1px solid var(--border, rgba(148,163,184,0.18));
+  border-radius: 8px;
+  cursor: pointer;
+  transition: border-color .15s, color .15s, background .15s;
+}
+.puro-locale-btn:hover:not(:disabled) {
+  border-color: var(--border-2, rgba(148,163,184,0.32));
+  color: var(--cyan, #22d3ee);
+}
+.puro-locale-btn:disabled { opacity: 0.6; cursor: not-allowed; }
+.puro-locale-code { letter-spacing: 0.08em; }
+.puro-locale-chev { color: var(--text-3, #64748b); transition: transform .15s; }
+.puro-locale-chev.open { transform: rotate(180deg); color: var(--cyan, #22d3ee); }
+
+.puro-locale-menu {
+  position: absolute; top: calc(100% + 6px); right: 0;
+  min-width: 140px;
+  background: rgba(15, 23, 42, 0.95);
+  border: 1px solid var(--border, rgba(148,163,184,0.18));
+  border-radius: 10px;
+  padding: 4px;
+  box-shadow: 0 10px 30px -10px rgba(0,0,0,0.5);
+  backdrop-filter: blur(8px);
+  z-index: 50;
+}
+
+.puro-locale-option {
+  width: 100%;
+  display: flex; align-items: center; gap: 10px;
+  padding: 8px 10px;
+  background: transparent; border: none; border-radius: 6px;
+  font-size: 13px; color: var(--text-1, #cbd5e1);
+  cursor: pointer;
+  text-align: left;
+  transition: background .12s, color .12s;
+}
+.puro-locale-option:hover:not(:disabled) {
+  background: rgba(34, 211, 238, 0.08);
+  color: var(--text-0, #f8fafc);
+}
+.puro-locale-option.active {
+  color: var(--cyan, #22d3ee);
+}
+.puro-locale-option-code {
+  font-family: var(--font-mono);
+  font-size: 11px; letter-spacing: 0.08em;
+  color: var(--text-3, #64748b);
+}
+.puro-locale-option.active .puro-locale-option-code { color: var(--cyan, #22d3ee); }
+.puro-locale-option-name { flex: 1; }
+.puro-locale-option-dot {
+  width: 6px; height: 6px; border-radius: 50%;
+  background: var(--cyan, #22d3ee);
+  box-shadow: 0 0 0 3px rgba(34,211,238,0.2);
+}
+
+.puro-locale-pop-enter-active,
+.puro-locale-pop-leave-active { transition: opacity .12s, transform .12s; }
+.puro-locale-pop-enter-from,
+.puro-locale-pop-leave-to { opacity: 0; transform: translateY(-4px) scale(0.97); }
+</style>