Constrain admin plugin logo size to recommended 256x256 dimensions (#349)

Use inline styles instead of Tailwind classes for the logo preview in
the admin plugin edit form, since Filament's CSS build doesn't include
classes from inline HTML strings.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: simonhamp

app/Filament/Resources/PluginResource.php

@@ -52,7 +52,7 @@ public static function form(Schema $schema): Schema
                         Forms\Components\Placeholder::make('logo_preview')
                             ->label('Logo')
                             ->content(fn (?Plugin $record) => $record?->hasLogo()
-                                ? new HtmlString('<img src="'.e($record->getLogoUrl()).'" alt="Logo" class="w-16 h-16 rounded-lg object-cover" />')
+                                ? new HtmlString('<img src="'.e($record->getLogoUrl()).'" alt="Logo" style="max-width: 256px; max-height: 256px; border-radius: 0.5rem; object-fit: cover;" />')
                                 : 'No logo')
                             ->visible(fn (?Plugin $record) => $record !== null),