feat(api): add sign required-article endpoint

GET /api/sign/required_article returns one random article from the
"签到广告" article category (status=1, is_del=0, hidden=0). Empty
category or no articles returns null so clients can fall through to
direct sign-in. Powers the pre-sign-in reading gate per
docs/project-shaoyaoju/prd-require.md §6.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

pro_v3.5.1/app/controller/api/v1/user/UserSign.php

@@ -6,6 +6,7 @@
 namespace app\controller\api\v1\user;
 
 use app\Request;
+use app\services\article\ArticleServices;
 use app\services\user\member\MemberCardServices;
 use app\services\user\UserServices;
 use app\services\user\UserSignServices;
@@ -147,4 +148,26 @@ class UserSign
         $this->services->setSignRemind($uid, $status);
         return app('json')->success('设置成功');
     }
+
+    /**
+     * 签到前置阅读：从"签到广告"分类下随机返回一篇文章
+     * 分类不存在 / 无文章 时返回 null，前端跳过门槛直接签到
+     */
+    public function required_article(ArticleServices $articleServices)
+    {
+        $article = $articleServices->getRandomByCategoryTitle('签到广告');
+        if (!$article) {
+            return app('json')->successful(null);
+        }
+        $img = $article['image_input'] ?? '';
+        if (is_array($img)) {
+            $img = $img[0] ?? '';
+        }
+        return app('json')->successful([
+            'id'                    => (int)($article['id'] ?? 0),
+            'title'                 => (string)($article['title'] ?? ''),
+            'image'                 => (string)$img,
+            'view_required_seconds' => 10,
+        ]);
+    }
 }

pro_v3.5.1/app/services/article/ArticleServices.php

@@ -119,6 +119,37 @@ class ArticleServices extends BaseServices
         return $this->dao->update($id, ['product_id' => $product_id]);
     }
 
+    /**
+     * 按分类标题获取一条随机文章（用于签到前置阅读门槛）
+     * @param string $categoryTitle 分类标题（如"签到广告"）
+     * @return array|null id/title/image_input/visit；分类或文章不存在时返回 null
+     */
+    public function getRandomByCategoryTitle(string $categoryTitle)
+    {
+        /** @var ArticleCategoryServices $categoryServices */
+        $categoryServices = app()->make(ArticleCategoryServices::class);
+        $cat = $categoryServices->getOne([
+            'title'  => $categoryTitle,
+            'status' => 1,
+            'is_del' => 0,
+            'hidden' => 0,
+        ], 'id');
+        if (!$cat) {
+            return null;
+        }
+        $where = ['cid' => (int)$cat['id'], 'status' => 1, 'hide' => 0];
+        $ids = $this->dao->getColumn($where, 'id');
+        if (!$ids) {
+            return null;
+        }
+        $pickId = (int)$ids[array_rand($ids)];
+        $article = $this->dao->getOne(['id' => $pickId], 'id,title,image_input,visit,add_time');
+        if (!$article) {
+            return null;
+        }
+        return is_array($article) ? $article : $article->toArray();
+    }
+
     /**
      * 获取数量
      * @param array $where

pro_v3.5.1/route/api.php

@@ -275,6 +275,7 @@ Route::group('api', function () {
         Route::post('sign/integral', 'v1.user.UserSign/sign_integral')->middleware(BlockerMiddleware::class)->name('signIntegral');//签到
         Route::get('sign/remind/:status', 'v1.user.UserSign/sign_remind')->name('signRemind');//用户设置签到提醒
         Route::get('sign/calendar', 'v1.user.UserSign/sign_calendar')->name('signCalendar');//日历数据
+        Route::get('sign/required_article', 'v1.user.UserSign/required_article')->name('signRequiredArticle');//签到前置阅读文章（"签到广告"分类随机一条）
         //优惠券类
         Route::post('coupon/receive', 'v1.activity.StoreCoupons/receive')->middleware(BlockerMiddleware::class)->name('couponReceive'); //领取优惠券
         Route::post('coupon/receive/batch', 'v1.activity.StoreCoupons/receive_batch')->name('couponReceiveBatch'); //批量领取优惠券