fix: add type=button to media picker modal buttons

Prevents form validation from being triggered when clicking
the close button or load more button inside the modal.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/templates/shared/macros/modals.html

@@ -770,6 +770,7 @@
                     {% endif %}
                 </h3>
                 <button
+                    type="button"
                     @click="{{ show_var }} = false"
                     class="p-2 text-gray-400 hover:text-gray-600 dark:hover:text-gray-300 hover:bg-gray-100 dark:hover:bg-gray-700 rounded-lg transition-colors"
                 >
@@ -870,6 +871,7 @@
                 {# Pagination #}
                 <div x-show="mediaPickerState.total > mediaPickerState.media.length" class="mt-4 text-center">
                     <button
+                        type="button"
                         @click="loadMoreMedia()"
                         :disabled="mediaPickerState.loading"
                         class="px-4 py-2 text-sm text-purple-600 dark:text-purple-400 hover:bg-purple-50 dark:hover:bg-purple-900/20 rounded-lg transition-colors disabled:opacity-50"