feat: P4.6 agent demo + escalate button + support seed/smoke (P4 complete)

apps/agent-demo (Vite): agent sets AVAILABLE, sees assigned tickets, opens the
thread, replies. message-demo customer pane gains 'escalate to support' (via
SupportProvider/useEscalate). seed-support + smoke-support prove the loop:
escalate -> auto-assign -> agent reply -> customer receives. 45 tests; realtime/
inbox/support smokes all pass; both demos build.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/agent-demo/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "agent-demo",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite --port 5174",
+    "build": "vite build"
+  },
+  "dependencies": {
+    "@insignia/iios-kernel-client": "workspace:*",
+    "@insignia/iios-message-web": "workspace:*",
+    "@insignia/iios-support-web": "workspace:*",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0"
+  },
+  "devDependencies": {
+    "@types/react": "^19.0.0",
+    "@types/react-dom": "^19.0.0",
+    "@vitejs/plugin-react": "^4.3.4",
+    "typescript": "^5.7.3",
+    "vite": "^6.0.7"
+  }
+}