feat: initial IQAI multi-model AI dashboard

- Express backend with Replicate API proxy (chat, models, account, search)
- React + Vite + Tailwind frontend with custom Midnight Violet color scheme
- @mention autocomplete to route messages to specific models
- Parallel multi-model queries with model selection in sidebar
- DuckDuckGo web search context injection
- Model manager UI (add/edit/remove Replicate models)
- Per-model system instructions per conversation
- Replicate account info display in sidebar
- Conversation history with local persistence (Zustand)
- Full Docker deployment (backend + nginx-served frontend)
- Montserrat + Poppins fonts

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

frontend/package.json

@@ -0,0 +1,26 @@
+{
+  "name": "iqai-frontend",
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-markdown": "^9.0.1",
+    "remark-gfm": "^4.0.0",
+    "react-syntax-highlighter": "^15.5.0",
+    "zustand": "^4.5.2",
+    "lucide-react": "^0.447.0"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-react": "^4.3.1",
+    "autoprefixer": "^10.4.20",
+    "postcss": "^8.4.47",
+    "tailwindcss": "^3.4.13",
+    "vite": "^5.4.8"
+  }
+}