wger: 2.3 -> 2.6

Campaign 7 catalog sweep.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nn3VgQk9iwEGgyx6QJ2NvE

templates/wger/docker-compose.yml

@@ -9,7 +9,7 @@
 
 services:
   wger:
-    image: wger/server:2.3
+    image: wger/server:2.6
     container_name: wger
     restart: unless-stopped
     environment: