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>

backend/data/models.json

@@ -0,0 +1,70 @@
+[
+  {
+    "id": "claude-opus-4",
+    "tag": "claude",
+    "displayName": "Claude Opus 4.6",
+    "owner": "anthropic",
+    "name": "claude-opus-4.6",
+    "type": "text",
+    "avatar": "🤖",
+    "color": "#CC785C",
+    "description": "Anthropic's most powerful model",
+    "systemPromptParam": "system_prompt",
+    "defaultInput": {
+      "max_tokens": 8192,
+      "max_image_resolution": 0.5
+    }
+  },
+  {
+    "id": "grok-4",
+    "tag": "grok",
+    "displayName": "Grok 4",
+    "owner": "xai",
+    "name": "grok-4",
+    "type": "text",
+    "avatar": "⚡",
+    "color": "#1DA1F2",
+    "description": "xAI's advanced reasoning model",
+    "systemPromptParam": null,
+    "defaultInput": {
+      "max_tokens": 2048,
+      "temperature": 0.1
+    }
+  },
+  {
+    "id": "gemini-3-pro",
+    "tag": "gemini",
+    "displayName": "Gemini 3.1 Pro",
+    "owner": "google",
+    "name": "gemini-3.1-pro",
+    "type": "text",
+    "avatar": "✨",
+    "color": "#4285F4",
+    "description": "Google's latest multimodal model",
+    "systemPromptParam": null,
+    "defaultInput": {
+      "temperature": 1,
+      "thinking_level": "high",
+      "max_output_tokens": 65535,
+      "top_p": 0.95,
+      "images": [],
+      "videos": []
+    }
+  },
+  {
+    "id": "deepseek-r1",
+    "tag": "deepseek",
+    "displayName": "DeepSeek R1",
+    "owner": "deepseek-ai",
+    "name": "deepseek-r1",
+    "type": "text",
+    "avatar": "🔍",
+    "color": "#7C3AED",
+    "description": "DeepSeek's advanced reasoning model",
+    "systemPromptParam": "system_prompt",
+    "defaultInput": {
+      "max_tokens": 8192,
+      "temperature": 0.7
+    }
+  }
+]