fix: modal click.outside race condition closing modal immediately

Replace @click.outside on modal panel with @click.stop — the backdrop
already handles closing. @click.outside fires from the same click event
that opens the modal via x-if, immediately setting showModal back to false.

_includes/layouts/post.njk

@@ -123,7 +123,7 @@ withBlogSidebar: true
                    x-transition:leave="transition ease-in duration-150"
                    x-transition:leave-start="opacity-100 scale-100"
                    x-transition:leave-end="opacity-0 scale-95"
-                   @click.outside="showModal = false">
+                   @click.stop>
                 <h3 class="text-lg font-semibold text-surface-900 dark:text-surface-100 mb-1">Fediverse Interaction</h3>
                 <p class="text-sm text-surface-500 dark:text-surface-400 mb-4">Enter your instance to like, boost, or reply.</p>
                 <input x-ref="instanceInput"