Fix blog post: use 4.1 thumbnail, single author (nik)

- Create dblab-4.1-blog.png thumbnail (was using 4.0 image)
- Change authors from [nik, bogdan] to just nik
- Update blog.js index to reference new thumbnail

https://claude.ai/code/session_01UjvipgoS6qs1ikzifd77Xi

Author: claude

blog/20260408-dblab-engine-4-1-released.md

@@ -1,11 +1,11 @@
 ---
-authors: [nik, bogdan]
+authors: nik
 date: 2026-04-08 00:00:00
 publishDate: 2026-04-08 00:00:00
 linktitle: "DBLab 4.1: protection leases, Teleport, Prometheus, and more"
 title: "DBLab 4.1: protection leases, Teleport, Prometheus, and more"
 weight: 0
-image: /assets/thumbnails/dblab-4.0-blog.png
+image: /assets/thumbnails/dblab-4.1-blog.png
 tags:
   - Product announcements
   - DBLab Engine

src/data/blog.js

@@ -5,7 +5,7 @@ const blog = [
     date: '2026-04-08 00:00:00',
     title: 'DBLab 4.1: protection leases, Teleport, Prometheus, and more',
     description: 'DBLab Engine 4.1 brings protection leases for safe clone management, Teleport integration, RDS/Aurora-safe refresh, Prometheus metrics, ARM64 support, and database rename.',
-    image: '/assets/thumbnails/dblab-4.0-blog.png',
+    image: '/assets/thumbnails/dblab-4.1-blog.png',
   },
   {
     link: 'blog/20241003-how-does-planning-time-depend-on-number-of-partitions',