📂 Add MIME type restrictions for 'main' media collection in ProjectProposal

app/Models/ProjectProposal.php

@@ -67,6 +67,12 @@ class ProjectProposal extends Model implements HasMedia
         $this
             ->addMediaCollection('main')
             ->singleFile()
+            ->acceptsMimeTypes([
+                'image/jpeg',
+                'image/png',
+                'image/gif',
+                'image/webp',
+            ])
             ->useFallbackUrl(asset('einundzwanzig-alpha.jpg'));
     }