tests + version bump: group chat surface

Extends chat.test.js to cover the new conversation shape (kind/key
fields), the /api/chat/rooms endpoint, the thread-settings
round-trip, and the group-creation pick-view toggle. Room-info view
DOM is structurally checked. Bumps to 1.9.4.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

electron/package.json

@@ -1,6 +1,6 @@
 {
   "name": "hyprcrd",
-  "version": "1.9.3",
+  "version": "1.9.4",
   "description": "hyprcrd — self-hosted card manager",
   "main": "main.js",
   "scripts": {