feat: 外链中转 /go——点击统计 + 拦截 + 隐藏真实链接

- redirects 表 + UrlRedirector：go_url() 站外链接改写为 /go/{hash}（确定性 hash、同 URL 复用、并发安全、缓存）
- /go/{hash} 302 跳转 + 点击计数 + 最后点击时间；停用状态 410（二次拦截）；后台「外链中转」资源可查看点击量/启停/删除
- 接入点：正文外链（渲染器统一改写）、评论正文自动链接（comment_body）、评论作者网址、友链（侧边栏+友链页）；站内/相对/mailto/tel/锚点不中转
- 测试 6 个（改写/计数/拦截/复用/渲染/评论正文）；README 补充

tests/Feature/AdminPagesTest.php

@@ -55,6 +55,7 @@ class AdminPagesTest extends TestCase
         $this->actingAs($this->admin)->get('/admin/plugins')->assertOk();
         $this->actingAs($this->admin)->get('/admin/payments')->assertOk();
         $this->actingAs($this->admin)->get('/admin/ai-settings')->assertOk();
+        $this->actingAs($this->admin)->get('/admin/redirects')->assertOk();
     }
 
     public function test_guest_is_redirected_to_login(): void

tests/Feature/GoRedirectTest.php

@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature;
+
+use App\Blog\Services\PostContentRenderer;
+use App\Blog\Services\UrlRedirector;
+use App\Models\Post;
+use App\Models\Redirect;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class GoRedirectTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_go_url_rewrites_external_but_keeps_internal(): void
+    {
+        $go = app(UrlRedirector::class);
+
+        $this->assertStringContainsString('/go/', $go->goUrl('https://example.com/path'));
+        $this->assertSame('http://laralog.test/posts/1', $go->goUrl('http://laralog.test/posts/1'));
+        $this->assertSame('/posts/1', $go->goUrl('/posts/1'));
+        $this->assertSame('mailto:a@b.com', $go->goUrl('mailto:a@b.com'));
+        $this->assertSame('#anchor', $go->goUrl('#anchor'));
+    }
+
+    public function test_go_redirect_counts_clicks(): void
+    {
+        $redirect = Redirect::create([
+            'hash' => 'abc123def0',
+            'target_url' => 'https://example.com/target',
+        ]);
+
+        $this->get('/go/abc123def0')
+            ->assertRedirect('https://example.com/target');
+
+        $redirect->refresh();
+        $this->assertSame(1, $redirect->clicks);
+        $this->assertNotNull($redirect->last_clicked_at);
+    }
+
+    public function test_disabled_redirect_returns_410(): void
+    {
+        Redirect::create([
+            'hash' => 'blocked0000',
+            'target_url' => 'https://example.com/bad',
+            'status' => 'disabled',
+        ]);
+
+        $this->get('/go/blocked0000')->assertStatus(410);
+    }
+
+    public function test_same_url_reuses_same_hash(): void
+    {
+        $a = app(UrlRedirector::class)->goUrl('https://example.com/dup');
+        $b = app(UrlRedirector::class)->goUrl('https://example.com/dup');
+
+        $this->assertSame($a, $b);
+        $this->assertSame(1, Redirect::query()->where('target_url', 'https://example.com/dup')->count());
+    }
+
+    public function test_post_render_rewrites_external_links(): void
+    {
+        $post = Post::create([
+            'title' => '外链测试',
+            'slug' => 'go-test',
+            'content' => "正文 <a href=\"https://example.com/x\" target=\"_blank\">外链</a> 和 <a href=\"http://laralog.test/posts/1\">站内</a>",
+            'content_format' => 'html',
+            'status' => 'published',
+            'published_at' => now(),
+        ]);
+
+        $html = app(PostContentRenderer::class)->render($post);
+
+        $this->assertStringContainsString('href="http://laralog.test/go/', $html);
+        $this->assertStringContainsString('href="http://laralog.test/posts/1"', $html);
+        $this->assertStringNotContainsString('href="https://example.com/x"', $html);
+    }
+
+    public function test_comment_body_autolinks_and_redirects(): void
+    {
+        $html = comment_body('看看 https://example.com/note 这个链接');
+
+        $this->assertStringContainsString('href="http://laralog.test/go/', $html);
+        $this->assertStringContainsString('rel="nofollow noopener"', $html);
+        $this->assertStringNotContainsString('href="https://example.com/note"', $html);
+    }
+}