feat: post cover filter + admin AI cover action, restyle page-cache admin

- 抽 CoverGenerator 服务（covers:generate 与后台共用），内部强制同步产出 card 转换
- 文章列表：新增封面状态图标列、「有/无封面/完全无图」筛选、行内「生成封面」AI 操作
- 页面缓存：统计改为原生 StatsOverviewWidget（缓存页数/总大小/命中率/时长），
  缓存明细表重排（表头、悬停、URL 截断、图标删除按钮、空状态）

app/Console/Commands/GenerateCovers.php

@@ -4,16 +4,13 @@ declare(strict_types=1);
 
 namespace App\Console\Commands;
 
-use App\Blog\Services\LlmClient;
+use App\Blog\Services\CoverGenerator;
 use App\Models\Post;
 use Illuminate\Console\Command;
-use Illuminate\Support\Facades\Http;
 use Illuminate\Support\Facades\Log;
-use Illuminate\Support\Str;
 
 /**
- * 用 AI 图像接口（OpenAI 兼容 /image_generation，如 MiniMax image-01）批量生成文章封面。
- * 复用「AI 设置」里的 llm_base_url / llm_api_key，模型取 llm_image_model（默认 image-01）。
+ * 批量为文章生成 AI 封面（默认只补完全没有任何图片的文章）。
  */
 class GenerateCovers extends Command
 {
@@ -27,18 +24,16 @@ class GenerateCovers extends Command
 
     protected $description = '用 AI 为文章批量生成封面图（存入 media cover 集合）';
 
-    public function handle(LlmClient $llm): int
+    public function handle(CoverGenerator $covers): int
     {
-        if (! $llm->isConfigured()) {
+        if (! $covers->isConfigured()) {
             $this->error('LLM 未配置：请先在后台「AI 设置」或 .env 配置 LLM_BASE_URL / LLM_API_KEY');
 
             return self::FAILURE;
         }
 
-        $model = (string) ($this->option('model') ?: blog_setting('llm_image_model', 'image-01'));
-
-        // 站点无常驻 queue worker：批量生成期间同步产出 card 转换，避免永远卡在队列里。
-        config(['media-library.queue_conversions_by_default' => false]);
+        $model = $covers->model($this->option('model') ?: null);
+        $style = $this->option('style') ?: null;
 
         $query = Post::query()->published()->orderedForList();
 
@@ -75,7 +70,7 @@ class GenerateCovers extends Command
 
         foreach ($todo as $post) {
             try {
-                $this->generateFor($post, $llm, $model);
+                $covers->generateFor($post, $model, $style);
                 $ok++;
                 $this->info("✔ [{$post->id}] {$post->title}");
             } catch (\Throwable $e) {
@@ -89,63 +84,4 @@ class GenerateCovers extends Command
 
         return $ok === 0 && $fail > 0 ? self::FAILURE : self::SUCCESS;
     }
-
-    private function generateFor(Post $post, LlmClient $llm, string $model): void
-    {
-        $response = Http::timeout(120)
-            ->withToken($llm->apiKey())
-            ->post($llm->baseUrl().'/image_generation', [
-                'model' => $model,
-                'prompt' => $this->buildPrompt($post),
-                'aspect_ratio' => '16:9',
-                'response_format' => 'url',
-                'n' => 1,
-                'prompt_optimizer' => true,
-            ]);
-
-        if ($response->failed()) {
-            throw new \RuntimeException('HTTP '.$response->status().'：'.Str::limit($response->body(), 200));
-        }
-
-        $url = $response->json('data.image_urls.0');
-        if (! is_string($url) || $url === '') {
-            $reason = $response->json('base_resp.status_msg') ?: $response->body();
-
-            throw new \RuntimeException('接口未返回图片：'.Str::limit((string) $reason, 200));
-        }
-
-        $image = Http::timeout(60)->get($url)->throw();
-        $ext = match (strtolower(explode(';', (string) $image->header('Content-Type'))[0])) {
-            'image/png' => 'png',
-            'image/webp' => 'webp',
-            default => 'jpg',
-        };
-
-        $tmp = tempnam(sys_get_temp_dir(), 'cover_');
-        file_put_contents($tmp, $image->body());
-
-        try {
-            $post->addMedia($tmp)
-                ->usingFileName('cover-'.$post->id.'.'.$ext)
-                ->toMediaCollection('cover');
-        } finally {
-            @unlink($tmp);
-        }
-    }
-
-    private function buildPrompt(Post $post): string
-    {
-        $style = trim((string) ($this->option('style')
-            ?: blog_setting('cover_prompt_style', '扁平插画风格，色调柔和，构图简洁')));
-        $excerpt = Str::limit(trim(strip_tags((string) $post->excerpt)), 60, '');
-
-        $parts = ["为博客文章《{$post->title}》生成一张封面配图"];
-        if ($excerpt !== '') {
-            $parts[] = "内容大意：{$excerpt}";
-        }
-        $parts[] = $style;
-        $parts[] = '画面中不要出现任何文字';
-
-        return implode('。', $parts);
-    }
 }