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/Blog/Services/CoverGenerator.php

@@ -0,0 +1,94 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Blog\Services;
+
+use App\Models\Post;
+use Illuminate\Support\Facades\Http;
+use Illuminate\Support\Str;
+
+/**
+ * AI 封面生成：复用「AI 设置」的 LLM 配置调 OpenAI 兼容 /image_generation 接口
+ * （如 MiniMax image-01），图片存入 media cover 集合（singleFile，重复生成自动替换）。
+ */
+class CoverGenerator
+{
+    public function __construct(private LlmClient $llm) {}
+
+    public function isConfigured(): bool
+    {
+        return $this->llm->isConfigured();
+    }
+
+    public function model(?string $override = null): string
+    {
+        return $override ?: (string) blog_setting('llm_image_model', 'image-01');
+    }
+
+    public function generateFor(Post $post, ?string $model = null, ?string $style = null): void
+    {
+        if (! $this->llm->isConfigured()) {
+            throw new \RuntimeException('LLM 未配置：请先在后台「AI 设置」配置 Base URL / API Key');
+        }
+
+        // 站点无常驻 queue worker：同步产出 card 转换，避免缩略图永远卡在队列里。
+        config(['media-library.queue_conversions_by_default' => false]);
+
+        $response = Http::timeout(120)
+            ->withToken($this->llm->apiKey())
+            ->post($this->llm->baseUrl().'/image_generation', [
+                'model' => $this->model($model),
+                'prompt' => $this->buildPrompt($post, $style),
+                'aspect_ratio' => '16:9',
+                'response_format' => 'url',
+                'n' => 1,
+                'prompt_optimizer' => true,
+            ]);
+
+        if ($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);
+        }
+    }
+
+    public function buildPrompt(Post $post, ?string $style = null): string
+    {
+        $style = trim((string) ($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);
+    }
+}

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);
-    }
 }

app/Filament/Pages/PageCache.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace App\Filament\Pages;
 
 use App\Blog\Support\PageCacheMiddleware;
+use App\Filament\Widgets\PageCacheStats;
 use App\Models\Setting;
 use Filament\Actions\Action;
 use Filament\Notifications\Notification;
@@ -28,18 +29,7 @@ class PageCache extends Page
     protected string $view = 'filament.pages.page-cache';
 
     /**
-     * @return array{hits: int, misses: int, count: int, rate: float, ttl: int}
-     */
-    public function getStatsProperty(): array
-    {
-        return [
-            ...PageCacheMiddleware::stats(),
-            'ttl' => (int) config('blog.page_cache_ttl', 300),
-        ];
-    }
-
-    /**
-     * @return list<array{key: string, url: string, cached_at: string}>
+     * @return list<array{key: string, url: string, cached_at: string, size: int, expires_at: string}>
      */
     public function getEntriesProperty(): array
     {
@@ -72,6 +62,13 @@ class PageCache extends Page
         Notification::make()->title('已删除这条缓存')->success()->send();
     }
 
+    protected function getHeaderWidgets(): array
+    {
+        return [
+            PageCacheStats::class,
+        ];
+    }
+
     protected function getHeaderActions(): array
     {
         return [

app/Filament/Resources/Posts/Tables/PostsTable.php

@@ -4,17 +4,21 @@ declare(strict_types=1);
 
 namespace App\Filament\Resources\Posts\Tables;
 
+use App\Blog\Services\CoverGenerator;
 use App\Models\Post;
 use Filament\Actions\Action;
 use Filament\Actions\BulkActionGroup;
 use Filament\Actions\DeleteBulkAction;
 use Filament\Actions\EditAction;
 use Filament\Actions\ViewAction;
+use Filament\Notifications\Notification;
 use Filament\Support\Enums\Width;
+use Filament\Tables\Columns\IconColumn;
 use Filament\Tables\Columns\TextColumn;
 use Filament\Tables\Enums\FiltersLayout;
 use Filament\Tables\Filters\SelectFilter;
 use Filament\Tables\Table;
+use Illuminate\Database\Eloquent\Builder;
 
 class PostsTable
 {
@@ -46,6 +50,16 @@ class PostsTable
                         'draft' => 'warning',
                         default => 'gray',
                     }),
+                IconColumn::make('cover_state')
+                    ->label('封面')
+                    ->boolean()
+                    ->trueIcon('heroicon-o-photo')
+                    ->falseIcon('heroicon-o-x-mark')
+                    ->trueColor('success')
+                    ->falseColor('gray')
+                    ->state(fn (Post $record): bool => $record->coverImageUrl() !== null)
+                    ->tooltip(fn (Post $record): string => $record->coverImageUrl() !== null ? '已有封面' : '无封面，可用「生成封面」AI 补一张')
+                    ->toggleable(),
                 TextColumn::make('sticky_level')
                     ->label('置顶')
                     ->badge()
@@ -90,10 +104,50 @@ class PostsTable
                 SelectFilter::make('sticky_level')
                     ->label('置顶')
                     ->options(Post::stickyLevelOptions()),
+                SelectFilter::make('cover_status')
+                    ->label('封面')
+                    ->options([
+                        'with' => '有封面',
+                        'without' => '无封面',
+                        'no_image' => '完全无图（正文/附件也没有）',
+                    ])
+                    ->query(fn (Builder $query, array $data): Builder => match ($data['value'] ?? null) {
+                        'with' => $query->where(fn (Builder $q) => $q
+                            ->whereNotNull('cover_media_id')
+                            ->orWhereHas('media', fn (Builder $m) => $m->where('collection_name', 'cover'))),
+                        'without' => $query
+                            ->whereNull('cover_media_id')
+                            ->whereDoesntHave('media', fn (Builder $m) => $m->where('collection_name', 'cover')),
+                        'no_image' => $query
+                            ->whereNull('cover_media_id')
+                            ->whereDoesntHave('media', fn (Builder $m) => $m->where(fn (Builder $x) => $x
+                                ->where('collection_name', 'cover')
+                                ->orWhere(fn (Builder $y) => $y
+                                    ->where('collection_name', 'attachments')
+                                    ->where('mime_type', 'like', 'image/%'))))
+                            ->where('content', 'not like', '%<img%')
+                            ->where('content', 'not like', '%](http%'),
+                        default => $query,
+                    }),
             ], FiltersLayout::AboveContent)
             ->filtersFormColumns(3)
             ->filtersFormWidth(Width::ThreeExtraLarge)
             ->recordActions([
+                Action::make('generateCover')
+                    ->label('生成封面')
+                    ->icon('heroicon-o-photo')
+                    ->color('gray')
+                    ->requiresConfirmation()
+                    ->modalHeading('AI 生成封面')
+                    ->modalDescription(fn (Post $record): string => "根据《{$record->title}》的标题和摘要生成一张封面图，约需 20 秒，请耐心等待。")
+                    ->action(function (Post $record): void {
+                        try {
+                            app(CoverGenerator::class)->generateFor($record);
+                            Notification::make()->title('封面已生成')->success()->send();
+                        } catch (\Throwable $e) {
+                            Notification::make()->title('生成失败')->body($e->getMessage())->danger()->send();
+                        }
+                    }),
                 Action::make('preview')
                     ->label('预览')
                     ->url(fn (Post $record): string => $record->url)

app/Filament/Widgets/PageCacheStats.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Filament\Widgets;
+
+use App\Blog\Support\PageCacheMiddleware;
+use Filament\Widgets\StatsOverviewWidget;
+use Filament\Widgets\StatsOverviewWidget\Stat;
+
+class PageCacheStats extends StatsOverviewWidget
+{
+    protected function getStats(): array
+    {
+        $stats = PageCacheMiddleware::stats();
+        $size = (int) collect(PageCacheMiddleware::entries())->sum('size');
+        $sizeText = $size >= 1048576
+            ? number_format($size / 1048576, 2).' MB'
+            : number_format($size / 1024, 1).' KB';
+
+        return [
+            Stat::make('缓存页面', $stats['count'].' 个')
+                ->description('仅未登录访客的 GET 页面')
+                ->icon('heroicon-m-document-text'),
+            Stat::make('总大小', $sizeText)
+                ->description('全部缓存页合计')
+                ->icon('heroicon-m-circle-stack'),
+            Stat::make('命中率', $stats['rate'].'%')
+                ->description("命中 {$stats['hits']} · 未命中 {$stats['misses']}")
+                ->icon('heroicon-m-chart-bar'),
+            Stat::make('缓存时长', ((int) config('blog.page_cache_ttl', 300)).' 秒')
+                ->description('到期自动失效')
+                ->icon('heroicon-m-clock'),
+        ];
+    }
+}