feat(credits): free points tasks matrix, day cap, and tasks tab

Add AKSRT_Points_Free for catalog/day-max/daily detail, wire the full
earn matrix (login, post, like, favorite, follow, comment, forum),
expose 积分任务 + 每日详情 tabs, and expand admin free-task settings.

inc/classes/class-aksrt-signin.php

@@ -130,8 +130,19 @@ class AKSRT_Signin {
             return new WP_Error('aksrt_signin_dup', __('签到失败', 'aksrt'), ['status' => 409]);
         }
 
-        if ($reward > 0 && class_exists('AKSRT_Credits')) {
-            AKSRT_Credits::add($user_id, $reward, 'signin', ['type' => 'user', 'id' => $user_id]);
+        if ($reward > 0) {
+            if (class_exists('AKSRT_Points_Free')) {
+                $granted = AKSRT_Points_Free::grant_amount($user_id, $reward, 'sign_in', ['type' => 'user', 'id' => $user_id]);
+                if (is_wp_error($granted)) {
+                    if (class_exists('AKSRT_Credits')) {
+                        AKSRT_Credits::add($user_id, $reward, 'signin', ['type' => 'user', 'id' => $user_id]);
+                    }
+                } else {
+                    $reward = (int) $granted;
+                }
+            } elseif (class_exists('AKSRT_Credits')) {
+                AKSRT_Credits::add($user_id, $reward, 'signin', ['type' => 'user', 'id' => $user_id]);
+            }
         }
 
         return new WP_REST_Response([