refactor(契约): 展示题号统一叫 problemDisplayId，题单 id 统一叫 problemSetId

前后端同时改，部署前开着的旧页面要刷新一次（题号列会是空的、提交筛选会失效）。

- 挂在非题目对象上的展示题号，原来叫 problem（字符串）或 displayId，统一成
  problemDisplayId：提交列表、流程图列表、统计的 lastFailure / items /
  今日最热题、站内信里的提交、后台题单的题目列表。别处的 problem 都是对象
  或数字 id，这几处是字符串，最容易看错
- 列表筛选的 query 参数 ?problemId= 实际传的是展示题号，改成
  ?problemDisplayId=（提交列表、流程图列表、三个统计接口）
- 契约里 problemsetId / problemSetId、problemset / problemSet 两种拼法并存，
  统一成 problemSetId / problemSet，和 ProblemSet* 类型名、problem-sets
  路径、前端路由参数一致。drizzle 的列键跟表名走，没动
- aiDetail.user（用户名字符串，而契约里别的 user 都是对象）→ username。
  ai_analysis.data 里存的历史快照仍是 user，没有代码读回它
- 后台题单题目表的列是按字符串键 'displayId' 取的，类型检查抓不到，一并改

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

apps/web/src/oj/submission/components/TodayStatistics.vue

@@ -148,14 +148,18 @@ onMounted(async () => {
       <template v-if="stats.problems.length">
         <n-divider style="margin: 16px 0">今天最热的题</n-divider>
         <div class="rows">
-          <div class="row" v-for="row in stats.problems" :key="row.problem">
+          <div
+            class="row"
+            v-for="row in stats.problems"
+            :key="row.problemDisplayId"
+          >
             <n-button
               class="problem"
               text
               type="info"
-              @click="emit('openProblem', row.problem)"
+              @click="emit('openProblem', row.problemDisplayId)"
             >
-              {{ row.problem }} {{ row.problemTitle }}
+              {{ row.problemDisplayId }} {{ row.problemTitle }}
             </n-button>
             <n-text class="row-count" depth="3">
               {{ row.count }} 条 / 正确 {{ row.acceptedCount }}

apps/web/src/oj/submission/list.vue

@@ -160,7 +160,7 @@ async function listSubmissions() {
     if (query.language === "Flowchart") {
       const res = await getFlowchartSubmissions({
         username: query.username,
-        problemId: query.problem,
+        problemDisplayId: query.problem,
         myself: query.myself,
         offset,
         limit: query.limit,
@@ -173,7 +173,7 @@ async function listSubmissions() {
       const res = await getSubmissions({
         ...query,
         offset,
-        problemId: query.problem,
+        problemDisplayId: query.problem,
         contestId: (route.params.contestID as string) ?? "",
         language: query.language,
         today: query.today,
@@ -239,12 +239,12 @@ function problemClicked(row: SubmissionListItem | FlowchartSubmissionListItem) {
     const path = router.resolve({
       name: "contest problem",
       params: {
-        problemID: row.problem,
+        problemID: row.problemDisplayId,
       },
     })
     window.open(path.href, "_blank")
   } else {
-    window.open("/problem/" + row.problem, "_blank")
+    window.open("/problem/" + row.problemDisplayId, "_blank")
   }
 }
 
@@ -289,7 +289,7 @@ function consumePendingJump() {
     message.info("这一页没有可以查看的代码")
     return
   }
-  showCodePanel(row.id, row.problem)
+  showCodePanel(row.id, row.problemDisplayId)
 }
 
 function moveCodePanel(step: 1 | -1) {
@@ -297,7 +297,7 @@ function moveCodePanel(step: 1 | -1) {
   if (index === -1) return
   const next = viewableSubmissions.value[index + step]
   if (next) {
-    showCodePanel(next.id, next.problem)
+    showCodePanel(next.id, next.problemDisplayId)
     return
   }
   const page = query.page + step
@@ -390,7 +390,7 @@ const columns = computed(() => {
       render: (row) =>
         h(SubmissionLink, {
           submission: row,
-          onShowCode: () => showCodePanel(row.id, row.problem),
+          onShowCode: () => showCodePanel(row.id, row.problemDisplayId),
         }),
     },
     {
@@ -409,9 +409,9 @@ const columns = computed(() => {
           {
             type: "题目",
             onClick: () => problemClicked(row),
-            onSearch: () => (query.problem = row.problem),
+            onSearch: () => (query.problem = row.problemDisplayId),
           },
-          () => `${row.problem} ${row.problemTitle}`,
+          () => `${row.problemDisplayId} ${row.problemTitle}`,
         )
         // 从题单入口做出来的提交才有这个标记（后端只在提交时记来源），
         // 同一道题从普通题库刷的不会带。老提交里只有当年首次 AC 那条有
@@ -507,9 +507,9 @@ const flowchartColumns = computed(() => {
           {
             type: "题目",
             onClick: () => problemClicked(row),
-            onSearch: () => (query.problem = row.problem),
+            onSearch: () => (query.problem = row.problemDisplayId),
           },
-          () => `${row.problem} ${row.problemTitle}`,
+          () => `${row.problemDisplayId} ${row.problemTitle}`,
         ),
     },
     {