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/server.js

@@ -0,0 +1,39 @@
+import express from 'express';
+import cors from 'cors';
+import { readFile } from 'fs/promises';
+import { fileURLToPath } from 'url';
+import { dirname, join } from 'path';
+import dotenv from 'dotenv';
+
+dotenv.config();
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+// Lazy import routes after dotenv loaded
+const { chatRouter } = await import('./routes/chat.js');
+const { modelsRouter } = await import('./routes/models.js');
+const { accountRouter } = await import('./routes/account.js');
+const { searchRouter } = await import('./routes/search.js');
+
+const app = express();
+const PORT = process.env.PORT || 3001;
+const FRONTEND_URL = process.env.FRONTEND_URL || 'http://localhost:5173';
+
+app.use(cors({
+  origin: [FRONTEND_URL, 'http://localhost:80', 'http://localhost'],
+  credentials: true
+}));
+app.use(express.json({ limit: '10mb' }));
+
+app.use('/api/chat', chatRouter);
+app.use('/api/models', modelsRouter);
+app.use('/api/account', accountRouter);
+app.use('/api/search', searchRouter);
+
+// Health check
+app.get('/api/health', (req, res) => res.json({ status: 'ok', timestamp: new Date().toISOString() }));
+
+app.listen(PORT, '0.0.0.0', () => {
+  console.log(`IQAI Backend running on http://0.0.0.0:${PORT}`);
+  console.log(`API Token: ${process.env.REPLICATE_API_TOKEN ? '✓ configured' : '✗ NOT SET'}`);
+});