chore: add engines requirement (node >= 20) and bump version to 0.3.2

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hermes-web-ui",
-  "version": "0.3.1",
+  "version": "0.3.2",
   "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",
@@ -8,6 +8,9 @@
   },
   "homepage": "https://github.com/EKKOLearnAI/hermes-web-ui",
   "license": "MIT",
+  "engines": {
+    "node": ">=20.0.0"
+  },
   "keywords": [
     "hermes",
     "ai-agent",