feat: add i18n, platform channels page, and WeChat QR login

- Add vue-i18n with auto-detect browser language and manual toggle (EN/中文)
- Move platform channels to separate page with credential management
- Support Telegram, Discord, Slack, WhatsApp, Matrix, Feishu, Weixin, WeCom
- Add WeChat QR code login (opens in browser, polls status, auto-saves)
- Write platform credentials to ~/.hermes/.env matching hermes gateway setup
- Auto restart gateway after platform config changes
- Add settings store with per-section save for all config categories
- Persist session group collapse state across navigation
- Fix pre-existing TypeScript build errors

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

src/components/chat/MarkdownRenderer.vue

@@ -1,9 +1,11 @@
 <script setup lang="ts">
 import { computed } from 'vue'
+import { useI18n } from 'vue-i18n'
 import MarkdownIt from 'markdown-it'
 import hljs from 'highlight.js'
 
 const props = defineProps<{ content: string }>()
+const { t } = useI18n()
 
 const md: MarkdownIt = new MarkdownIt({
   html: false,
@@ -12,12 +14,12 @@ const md: MarkdownIt = new MarkdownIt({
   highlight(str: string, lang: string): string {
     if (lang && hljs.getLanguage(lang)) {
       try {
-        return `<pre class="hljs-code-block"><div class="code-header"><span class="code-lang">${lang}</span><button class="copy-btn" onclick="navigator.clipboard.writeText(this.closest('.hljs-code-block').querySelector('code').textContent)">Copy</button></div><code class="hljs language-${lang}">${hljs.highlight(str, { language: lang, ignoreIllegals: true }).value}</code></pre>`
+        return `<pre class="hljs-code-block"><div class="code-header"><span class="code-lang">${lang}</span><button class="copy-btn" onclick="navigator.clipboard.writeText(this.closest('.hljs-code-block').querySelector('code').textContent)">${t('common.copy')}</button></div><code class="hljs language-${lang}">${hljs.highlight(str, { language: lang, ignoreIllegals: true }).value}</code></pre>`
       } catch {
         // fall through
       }
     }
-    return `<pre class="hljs-code-block"><div class="code-header"><button class="copy-btn" onclick="navigator.clipboard.writeText(this.closest('.hljs-code-block').querySelector('code').textContent)">Copy</button></div><code class="hljs">${md.utils.escapeHtml(str)}</code></pre>`
+    return `<pre class="hljs-code-block"><div class="code-header"><button class="copy-btn" onclick="navigator.clipboard.writeText(this.closest('.hljs-code-block').querySelector('code').textContent)">${t('common.copy')}</button></div><code class="hljs">${md.utils.escapeHtml(str)}</code></pre>`
   },
 })