fix: 客户评价页补全截图/标签/关键词数据

- reviews表新增screenshot/scenes/concerns字段
- API映射从数据库读取这些字段，不再硬编码为空
- 修复客户高频关键词不显示的问题

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/database/schema.js

@@ -38,6 +38,9 @@ export const reviews = sqliteTable('reviews', {
   title: text('title'),
   content: text('content'),
   date: text('date'),
+  screenshot: text('screenshot'),        // 评价截图路径
+  scenes: text('scenes'),               // JSON数组: 出行场景标签
+  concerns: text('concerns'),           // JSON数组: 关注维度标签
   verified: integer('verified', { mode: 'boolean' }).default(false),
   published: integer('published', { mode: 'boolean' }).default(true),
   sortOrder: integer('sort_order').default(0),