refactor(题单): 难度、状态、分数、提示、总分、百分比和 problemset_submission 表不再读写，先补默认值、下一步再删

机房和服务器共用一个库、不一定同时升级，所以分两步退役：0027 只给还非空的几列补默认值，
新代码插行不用再填、没升级的那边照旧能跑；两个站点都换上新代码后，再单独一条迁移删列删表
（要手工放行破坏性迁移，语句写在 0027 的注释里）。

进度算法随之去掉分数和百分比，判题记进度不再往 problemset_submission 写一行（从来没人读）。

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

apps/api/src/routes/admin/problemset.ts

@@ -192,9 +192,6 @@ adminProblemSetRoutes.post("/problem-sets", requireTeacher, async (c) => {
       description: parsed.data.description,
       visible: parsed.data.visible,
       ...period,
-      // 难度、状态两列还在表里、非空，但已经不用了（见契约 admin.ts 的说明）
-      difficulty: "Easy",
-      status: "active",
       createdById: c.get("user")!.id,
       createTime: now,
       lastUpdateTime: now,
@@ -322,14 +319,7 @@ adminProblemSetRoutes.post("/problem-sets/:id/problems", requireTeacher, async (
     else {
       inSet.add(problem.id)
       order += 1
-      // 分数、提示两列还在表里但已经不用了：score 非空给 0
-      values.push({
-        problemsetId: row.id,
-        problemId: problem.id,
-        order,
-        isRequired: true,
-        score: 0,
-      })
+      values.push({ problemsetId: row.id, problemId: problem.id, order, isRequired: true })
       result.added.push(problem.displayId)
     }
   }
@@ -400,21 +390,8 @@ adminProblemSetRoutes.delete("/problem-sets/:id/problems/:itemId", requireTeache
         eq(schema.problemsetProblem.problemsetId, row.id),
       ),
     )
-    .returning({
-      id: schema.problemsetProblem.id,
-      problemId: schema.problemsetProblem.problemId,
-    })
+    .returning({ id: schema.problemsetProblem.id })
   if (deleted.length === 0) return failure(c, 404, "problem-not-in-set", "题目不在该题单中")
-  // 这道题在本题单里的提交记录也要清掉，对齐旧栈 problemset/signals.py 的 post_delete。
-  // 不清的话 problemset_submission 会一直攒指向已移出题单的孤儿行。
-  await db
-    .delete(schema.problemsetSubmission)
-    .where(
-      and(
-        eq(schema.problemsetSubmission.problemsetId, row.id),
-        eq(schema.problemsetSubmission.problemId, deleted[0]!.problemId),
-      ),
-    )
   await resyncProgress(row.id)
   return success(c, null)
 })

apps/api/src/routes/problemset.ts

@@ -368,7 +368,6 @@ problemsetRoutes.post("/problem-set-progress", requireAuth, async (c) => {
     const links = await tx
       .select({
         problemId: schema.problemsetProblem.problemId,
-        score: schema.problemsetProblem.score,
         isRequired: schema.problemsetProblem.isRequired,
       })
       .from(schema.problemsetProblem)