feat: Show last modified by user on document viewer

- Display updater name next to update time
- Fall back to creator if no updater is set
- Add modified_by translation for all 8 languages

src/resources/views/livewire/document-viewer.blade.php

@@ -20,15 +20,19 @@ class="inline-flex items-center px-4 py-2 bg-indigo-600 text-white text-sm font-
         </div>
 
         <div class="flex items-center text-sm text-gray-500 space-x-4">
-            @if($document->created_by)
-                <span>
-                    {{ __('messages.documents.created_by') }} {{ $document->creator->name }}
-                </span>
-            @endif
-
             <span>
                 {{ __('messages.documents.updated') }} {{ $document->updated_at->diffForHumans() }}
             </span>
+
+            @if($document->updated_by && $document->updater)
+                <span>
+                    {{ __('messages.documents.modified_by') }} {{ $document->updater->name }}
+                </span>
+            @elseif($document->created_by && $document->creator)
+                <span>
+                    {{ __('messages.documents.modified_by') }} {{ $document->creator->name }}
+                </span>
+            @endif
         </div>
     </div>