feat: add 6 new locales (ja, ko, fr, es, de, pt) and UI polish

- Add Japanese, Korean, French, Spanish, German, Portuguese translations
- Improve session active state visibility in both themes
- Static language labels in LanguageSwitch component
- Dark theme: lighten chat input background for better contrast
- Fix system theme listener not toggling back to light

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hermes-web-ui",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "Web dashboard for Hermes Agent — multi-platform AI chat, session management, scheduled jobs, usage analytics & channel configuration (Telegram, Discord, Slack, WhatsApp)",
   "repository": {
     "type": "git",