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/src/App.jsx

@@ -0,0 +1,43 @@
+import React, { useEffect } from 'react';
+import Sidebar from './components/Sidebar.jsx';
+import ChatArea from './components/ChatArea.jsx';
+import ModelManager from './components/ModelManager.jsx';
+import SystemPromptPanel from './components/SystemPromptPanel.jsx';
+import { useStore } from './store/useStore.js';
+
+export default function App() {
+  const { fetchModels, createConversation, conversations, activeConvId, sidebarOpen } = useStore();
+
+  useEffect(() => {
+    fetchModels().then(() => {
+      // Auto-create first conversation if none exists
+      const state = useStore.getState();
+      if (state.conversations.length === 0) {
+        state.createConversation();
+      } else if (!state.activeConvId) {
+        useStore.setState({ activeConvId: state.conversations[0].id });
+      }
+    });
+  }, []);
+
+  return (
+    <div className="flex h-screen overflow-hidden bg-midnight">
+      {/* Subtle background gradient */}
+      <div className="fixed inset-0 pointer-events-none">
+        <div className="absolute top-0 left-0 w-96 h-96 bg-grape/5 rounded-full blur-3xl -translate-x-1/2 -translate-y-1/2" />
+        <div className="absolute bottom-0 right-0 w-96 h-96 bg-blush/5 rounded-full blur-3xl translate-x-1/2 translate-y-1/2" />
+      </div>
+
+      {/* Layout */}
+      <Sidebar />
+
+      <main className="flex-1 flex flex-col min-w-0 relative">
+        <ChatArea />
+      </main>
+
+      {/* Modals / overlays */}
+      <ModelManager />
+      <SystemPromptPanel />
+    </div>
+  );
+}