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/routes/models.js

@@ -0,0 +1,84 @@
+import express from 'express';
+import { readFile, writeFile } from 'fs/promises';
+import { fileURLToPath } from 'url';
+import { dirname, join } from 'path';
+
+const router = express.Router();
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const MODELS_PATH = join(__dirname, '../data/models.json');
+
+async function loadModels() {
+  const raw = await readFile(MODELS_PATH, 'utf-8');
+  return JSON.parse(raw);
+}
+
+async function saveModels(models) {
+  await writeFile(MODELS_PATH, JSON.stringify(models, null, 2));
+}
+
+router.get('/', async (req, res) => {
+  try {
+    const models = await loadModels();
+    res.json(models);
+  } catch (err) {
+    res.status(500).json({ error: 'Failed to load models' });
+  }
+});
+
+router.post('/', async (req, res) => {
+  try {
+    const { tag, displayName, owner, name, type, avatar, color, description, systemPromptParam, defaultInput } = req.body;
+    if (!tag || !owner || !name || !displayName) {
+      return res.status(400).json({ error: 'Missing required fields: tag, owner, name, displayName' });
+    }
+    const models = await loadModels();
+    if (models.find(m => m.tag === tag)) {
+      return res.status(409).json({ error: `Tag @${tag} already exists` });
+    }
+    const newModel = {
+      id: `${owner}-${name}`.replace(/[^a-z0-9-]/gi, '-'),
+      tag: tag.toLowerCase().replace(/[^a-z0-9]/g, ''),
+      displayName,
+      owner,
+      name,
+      type: type || 'text',
+      avatar: avatar || '🤖',
+      color: color || '#6B7280',
+      description: description || '',
+      systemPromptParam: systemPromptParam || null,
+      defaultInput: defaultInput || {}
+    };
+    models.push(newModel);
+    await saveModels(models);
+    res.status(201).json(newModel);
+  } catch (err) {
+    res.status(500).json({ error: 'Failed to add model' });
+  }
+});
+
+router.put('/:id', async (req, res) => {
+  try {
+    const models = await loadModels();
+    const idx = models.findIndex(m => m.id === req.params.id);
+    if (idx === -1) return res.status(404).json({ error: 'Model not found' });
+    models[idx] = { ...models[idx], ...req.body, id: models[idx].id };
+    await saveModels(models);
+    res.json(models[idx]);
+  } catch (err) {
+    res.status(500).json({ error: 'Failed to update model' });
+  }
+});
+
+router.delete('/:id', async (req, res) => {
+  try {
+    const models = await loadModels();
+    const filtered = models.filter(m => m.id !== req.params.id);
+    if (filtered.length === models.length) return res.status(404).json({ error: 'Model not found' });
+    await saveModels(filtered);
+    res.json({ success: true });
+  } catch (err) {
+    res.status(500).json({ error: 'Failed to delete model' });
+  }
+});
+
+export { router as modelsRouter, loadModels };