feat: 添加PAYMENT_MAINTENANCE_MODE维护模式 + ServiceUnavailable错误

src/handlers/user.rs

@@ -16,8 +16,13 @@ pub async fn get_current_user_profile(
     info!("获取当前用户信息, 用户ID: {}", user_id);
 
     let user = db::get_user_by_id(pool.get_ref(), user_id).await?;
-    let is_paid_active = user.is_paid && 
-        user.paid_expires_at.map_or(true, |expires| expires > chrono::Utc::now());
+    let is_maintenance = std::env::var("PAYMENT_MAINTENANCE_MODE").ok() == Some("true".to_string());
+    let is_paid_active = if is_maintenance {
+        true
+    } else {
+        user.is_paid &&
+            user.paid_expires_at.map_or(true, |expires| expires > chrono::Utc::now())
+    };
     
     Ok(HttpResponse::Ok().json(serde_json::json!({
         "success": true,