feat(题目列表): SQL 题混在一般题里看不出来，点进去才发现不是写 C——和画流程图一样挂「SQL」标签，「全部类型」里也能单独筛

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/utils/types.ts

@@ -167,6 +167,7 @@ export interface ProblemRow {
   allowFlowchart: boolean
   showFlowchart: boolean
   hasAstRules: boolean
+  isSql: boolean
   solvedUsers: number
   triedUsers: number
 }