feat: add 'image/webp' to allowed upload MIME types

Signed-off-by: Tobias Dillig <tobias.dillig@frachtwerk.de>

lib/config/index.js

@@ -193,7 +193,8 @@ switch (config.imageUploadType) {
       'image/jpeg',
       'image/png',
       'image/gif',
-      'image/svg+xml'
+      'image/svg+xml',
+      'image/webp'
     ]
 }
 

public/docs/release-notes.md

@@ -5,6 +5,7 @@
 ### Enhancements
 
 - Added external link whitelist setting (`externalLinkWhitelist` in config.json or `CMD_EXTERNAL_LINK_WHITELIST`) to skip warning page for certain domains
+- Enabled `.webp` for file uploads (for all backends but `imgur`, since it does not support it)
 
 ## <i class="fa fa-tag"></i> 1.11.0 <i class="fa fa-calendar-o"></i> 2026-06-18