feat: add admin env badge, quick post button, and harden plugin enable

Show local/prod in the Filament topbar, jump to create post in one click, tighten sidebar spacing, and stop Hello World from 500ing when its tables are missing.

Co-authored-by: Cursor <cursoragent@cursor.com>

plugins/demo.hello-world/src/Filament/Pages/HelloWorldSettings.php

@@ -24,6 +24,8 @@ class HelloWorldSettings extends Page
 
     protected static ?string $title = 'Hello World 设置';
 
+    protected static ?string $slug = 'hello-world-settings';
+
     protected string $view = 'filament.pages.plugin-settings';
 
     public array $data = [];

plugins/demo.hello-world/src/Http/HelloWorldController.php

@@ -15,7 +15,9 @@ class HelloWorldController
      */
     public function index()
     {
-        $logs = HelloWorldLog::query()->with('comment')->latest()->limit(10)->get();
+        $logs = \Illuminate\Support\Facades\Schema::hasTable('hello_world_logs')
+            ? HelloWorldLog::query()->with('comment')->latest()->limit(10)->get()
+            : collect();
 
         $view = view('demo-hello::hello', ['logs' => $logs]);
         app(\App\Blog\View\Composers\SidebarComposer::class)->compose($view);

plugins/demo.hello-world/src/ServiceProvider.php

@@ -29,15 +29,21 @@ class ServiceProvider extends PluginServiceProvider
         $manager->addFilter('post.rendered', function (string $html, Post $post) {
             $greeting = (string) Setting::get('hello_world_greeting', '你好');
 
-            return preg_replace_callback(
-                '/\[hello\s+([^\]]+)\]/',
+            $replaced = preg_replace_callback(
+                '/\[hello\s+([^\]]+)\]/u',
                 fn (array $m) => '<span class="hello-world">'.$greeting.'，'.e($m[1]).'！</span>',
                 $html
             );
+
+            return is_string($replaced) ? $replaced : $html;
         }, 20);
 
         // 4. 动作示例：新评论创建时写日志（演示数据关联 + 钩子监听）
         $manager->addAction('comment.created', function (Comment $comment) {
+            if (! \Illuminate\Support\Facades\Schema::hasTable('hello_world_logs')) {
+                return;
+            }
+
             HelloWorldLog::create([
                 'comment_id' => $comment->id,
                 'note' => '捕获新评论：'.mb_substr($comment->content, 0, 30),