refactor: restructure project for multi-agent extensibility

- Migrate source to packages/client and packages/server directories
- Namespace all Hermes-specific code under hermes/ subdirectories
  (api/hermes/, components/hermes/, views/hermes/, stores/hermes/)
- Add hermes.* route names and /hermes/* path prefixes
- Upgrade @koa/router to v15, adapt path-to-regexp v8 syntax
- Fix proxy path rewriting: /api/hermes/v1/* → /v1/*, /api/hermes/* → /api/*
- Fix frontend API paths to match backend /api/hermes/* routes
- Fix WebSocket terminal path to /api/hermes/terminal
- Add proxyMiddleware for reliable unmatched route proxying
- Add profiles route module and hermes-cli profile commands
- Update CLAUDE.md development guide with new architecture
- Add Chinese README (README_zh.md)
- Add Web Terminal feature to README

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/client/src/components/layout/LanguageSwitch.vue

@@ -0,0 +1,30 @@
+<script setup lang="ts">
+import { computed } from 'vue'
+import { useI18n } from 'vue-i18n'
+import { NSelect } from 'naive-ui'
+
+const { locale, availableLocales, t } = useI18n()
+
+const options = computed(() =>
+  availableLocales.map(loc => ({
+    label: loc === 'zh' ? t('language.zh') : t('language.en'),
+    value: loc,
+  })),
+)
+
+function handleChange(val: string) {
+  locale.value = val
+  localStorage.setItem('hermes_locale', val)
+}
+</script>
+
+<template>
+  <NSelect
+    :value="locale"
+    :options="options"
+    size="tiny"
+    :consistent-menu-width="false"
+    class="input-sm"
+    @update:value="handleChange"
+  />
+</template>