feat: AI-генерация обложек + /api/stats + раздача /uploads

- services/covers.js: gpt-image-1, фиксированный стиль emerald-geometric, fallback на ошибки шлюза
- articles.generateAndSaveArticle: запускает обложку в setImmediate (не блокирует ответ)
- routes/articles: POST /backfill-covers для досгенерации
- routes/stats: статистика блога (статьи, слова, токены, просмотры)
- index.js: express.static на /uploads БЕЗ авторизации (публичные картинки)

src/routes/articles.js

@@ -49,4 +49,17 @@ router.post('/generate', async (req, res) => {
   }
 });
 
+
+// POST /api/articles/backfill-covers — досгенерировать обложки для статей без них
+router.post('/backfill-covers', async (req, res) => {
+  try {
+    const covers = require('../services/covers');
+    const limit = parseInt(req.body?.limit) || 3;
+    const result = await covers.backfillCovers({ limit });
+    res.json(result);
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
 module.exports = router;

src/routes/stats.js

@@ -0,0 +1,39 @@
+const express = require('express');
+const router = express.Router();
+const { query } = require('../config/db');
+
+// GET /api/stats — публичная статистика блога
+router.get('/', async (_, res) => {
+  try {
+    const { rows: countRow } = await query(
+      `SELECT
+         COUNT(*)::int as articles_count,
+         COALESCE(SUM(LENGTH(content) - LENGTH(REPLACE(content, ' ', '')) + 1), 0)::int as total_words,
+         COALESCE(SUM(reading_time), 0)::int as total_reading_min,
+         COALESCE(SUM(views), 0)::int as total_views
+       FROM articles WHERE status='published'`
+    );
+
+    const { rows: jobsRow } = await query(
+      `SELECT
+         COALESCE(SUM(tokens_in), 0)::int as tokens_in,
+         COALESCE(SUM(tokens_out), 0)::int as tokens_out,
+         COUNT(*)::int as jobs_done
+       FROM generation_jobs WHERE status='done' AND type='article'`
+    );
+
+    const { rows: latestRow } = await query(
+      `SELECT MAX(published_at) as latest FROM articles WHERE status='published'`
+    );
+
+    res.json({
+      ...countRow[0],
+      ...jobsRow[0],
+      latest_published: latestRow[0]?.latest || null,
+    });
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
+module.exports = router;