feat(看板娘): 记得你常错在哪，题目页上会主动开口，互动都记下来

- 按学生的行为挑话：最近 20 次提交里某类错特别多（运行出错细到 NameError、TypeError、
  ValueError、EOFError），再错这一类时点名说；今天做对第 3 道起偶尔数一数；
  第一次戳她有见面的话，戳得多了说「又是你」
- 题目页上主动开口：同一题错到第 5 次、连着 3 次没跑例子就交还错了、又犯老毛病、
  15 分钟没交没跑。比赛里不说，至少隔 3 分钟，同一件事一题一次，10 秒后收起
- 互动记进新表 mascot_event（0043）：点开、点按钮、主动开口、摸头、点烦、被拖走；
  只记看板娘这边的事，每人每分钟最多 30 条
- GET /mascot/profile 给最近的错类、今天做对几道、点过几次；门槛按本机生产快照定
  （266 人里运行出错 ≥3 的 87 人、答案错误 ≥5 的 82 人）
- 编辑过程（粘贴）数据学生侧不用，免得冤枉人

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

apps/api/src/db/0043_mascot_event.sql

@@ -0,0 +1,14 @@
+CREATE TABLE "mascot_event" (
+	"id" integer PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY (sequence name "mascot_event_id_seq" INCREMENT BY 1 MINVALUE 1 MAXVALUE 2147483647 START WITH 1 CACHE 1),
+	"user_id" integer NOT NULL,
+	"kind" text NOT NULL,
+	"situation" text,
+	"line" text,
+	"action" text,
+	"path" text NOT NULL,
+	"created_at" timestamp with time zone DEFAULT now() NOT NULL
+);
+--> statement-breakpoint
+ALTER TABLE "mascot_event" ADD CONSTRAINT "mascot_event_user_id_fk_user_id" FOREIGN KEY ("user_id") REFERENCES "public"."user"("id") ON DELETE cascade ON UPDATE no action;--> statement-breakpoint
+CREATE INDEX "mascot_event_user_kind_idx" ON "mascot_event" USING btree ("user_id","kind");--> statement-breakpoint
+CREATE INDEX "mascot_event_created_at_idx" ON "mascot_event" USING btree ("created_at");

apps/api/src/db/meta/_journal.json

@@ -302,6 +302,13 @@
       "when": 1793632543220,
       "tag": "0042_class_name_cleanup",
       "breakpoints": true
+    },
+    {
+      "idx": 43,
+      "version": "7",
+      "when": 1793693911394,
+      "tag": "0043_mascot_event",
+      "breakpoints": true
     }
   ]
 }

apps/api/src/db/schema.ts

@@ -46,6 +46,7 @@ import type {
   JudgeStatus,
   LessonLanguage,
   LessonMode,
+  MascotEventKind,
   ProblemChallenges,
   ProblemDifficulty,
   ProblemLanguage,
@@ -1411,3 +1412,45 @@ export const challengeSuccess = pgTable(
     }).onDelete('cascade'),
   ],
 )
+
+/**
+ * 看板娘的互动记录：点开气泡、点气泡里的按钮、她主动开口、摸头彩蛋、被拖走（种类见契约
+ * mascotEventSchema）。拿来看她说的话、给的按钮学生用不用，以后按学生的行为调整她也读这里；
+ * 「点过几次」（熟悉程度）直接按 user_id 数 open。
+ *
+ * 不是「学生做过什么」的证据，账号没了就没意义，user 外键 CASCADE（外键分档见 CLAUDE.md「数据库」）。
+ */
+export const mascotEvent = pgTable(
+  'mascot_event',
+  {
+    id: integer().primaryKey().generatedByDefaultAsIdentity({
+      name: 'mascot_event_id_seq',
+      startWith: 1,
+      increment: 1,
+      minValue: 1,
+      maxValue: 2147483647,
+      cache: 1,
+    }),
+    userId: integer('user_id').notNull(),
+    kind: text().$type<MascotEventKind>().notNull(),
+    situation: text(),
+    line: text(),
+    action: text(),
+    path: text().notNull(),
+    createdAt: timestamp('created_at', {
+      withTimezone: true,
+      mode: 'string',
+    })
+      .notNull()
+      .defaultNow(),
+  },
+  (table) => [
+    index('mascot_event_user_kind_idx').on(table.userId, table.kind),
+    index('mascot_event_created_at_idx').on(table.createdAt),
+    foreignKey({
+      columns: [table.userId],
+      foreignColumns: [user.id],
+      name: 'mascot_event_user_id_fk_user_id',
+    }).onDelete('cascade'),
+  ],
+)

apps/api/src/index.ts

@@ -21,6 +21,7 @@ import { problemRoutes } from './routes/problem'
 import { problemStatsRoutes } from './routes/problem-stats'
 import { submissionRoutes } from './routes/submission'
 import { trialRunRoutes } from './routes/trial-run'
+import { mascotRoutes } from './routes/mascot'
 import { siteRoutes } from './routes/site'
 import { scanPendingChallenges } from './services/challenge'
 import { bridgeSubmissionEvents, isAllowedWebSocketOrigin, startSessionSweep, submissionWebSocketHandler, type SubmissionSocketData } from './websocket'
@@ -44,6 +45,7 @@ app.route('/api', problemRoutes)
 app.route('/api', problemStatsRoutes)
 app.route('/api', submissionRoutes)
 app.route('/api', trialRunRoutes)
+app.route('/api', mascotRoutes)
 app.route('/api/admin', adminRoutes)
 
 // 没有这条的话，打错的接口地址回的是 Hono 默认的纯文本「404 Not Found」，前端 utils/api.ts 读不出

apps/api/src/routes/mascot.ts

@@ -0,0 +1,86 @@
+import { mascotEventSchema, type MascotProfile } from '@oj2/contract'
+import { and, count, countDistinct, desc, eq, gte, isNull, sql } from 'drizzle-orm'
+import { Hono } from 'hono'
+
+import { requireAuth, type AppEnv } from '../auth/middleware'
+import { db, schema } from '../db'
+import { parseBody, success } from '../http'
+import { dayStart } from '../time'
+
+export const mascotRoutes = new Hono<AppEnv>()
+
+/**
+ * 每人每分钟最多记这么多条。正常点她一分钟到不了十条（连点只记开头、彩蛋和嫌烦那几下），
+ * 拿脚本刷的才会撞上；撞上了就静默丢掉，不报错 —— 前台本来也不等这个结果
+ */
+const EVENTS_PER_MINUTE = 30
+const windows = new Map<number, { start: number; count: number }>()
+
+function allow(userId: number) {
+  const now = Date.now()
+  const entry = windows.get(userId)
+  if (!entry || now - entry.start >= 60_000) {
+    windows.set(userId, { start: now, count: 1 })
+    // 顺手清掉过期的，免得 Map 跟着在线人数一直涨
+    if (windows.size > 2000) for (const [id, it] of windows) if (now - it.start >= 60_000) windows.delete(id)
+    return true
+  }
+  entry.count++
+  return entry.count <= EVENTS_PER_MINUTE
+}
+
+/** 记一条看板娘互动（种类见契约 mascotEventSchema） */
+mascotRoutes.post('/mascot/events', requireAuth, async (c) => {
+  const parsed = await parseBody(c, mascotEventSchema, '看板娘记录的格式不对')
+  if (!parsed.success) return parsed.response
+  const user = c.get('user')!
+  if (allow(user.id)) {
+    const { kind, situation, line, action, path } = parsed.data
+    await db.insert(schema.mascotEvent).values({ userId: user.id, kind, situation, line, action, path })
+  }
+  return success(c, null)
+})
+
+/** 最近多少次题库提交拿来看学生常犯哪类错 */
+const RECENT_SUBMISSIONS = 20
+
+/** 看板娘按学生的行为挑话用的那几个数（契约 mascotProfileSchema） */
+mascotRoutes.get('/mascot/profile', requireAuth, async (c) => {
+  const userId = c.get('user')!.id
+  const s = schema.submission
+
+  const [pokes, today, recent] = await Promise.all([
+    db
+      .select({ value: count() })
+      .from(schema.mascotEvent)
+      .where(and(eq(schema.mascotEvent.userId, userId), eq(schema.mascotEvent.kind, 'open'))),
+    db
+      .select({ value: countDistinct(s.problemId) })
+      .from(s)
+      .where(and(eq(s.userId, userId), eq(s.result, 0), gte(s.createTime, dayStart()))),
+    db
+      .select({ result: s.result, errorType: sql<string | null>`${s.statisticInfo}->'runtime_error'->>'type'` })
+      .from(s)
+      .where(and(eq(s.userId, userId), isNull(s.contestId)))
+      .orderBy(desc(s.createTime))
+      .limit(RECENT_SUBMISSIONS),
+  ])
+
+  const types = new Map<string, number>()
+  for (const row of recent) if (row.result === 4 && row.errorType) types.set(row.errorType, (types.get(row.errorType) ?? 0) + 1)
+  const topType = [...types.entries()].sort((a, b) => b[1] - a[1])[0]?.[0] ?? null
+  const tally = (...results: number[]) => recent.filter((row) => results.includes(row.result)).length
+
+  return success(c, {
+    pokes: pokes[0]?.value ?? 0,
+    todaySolved: today[0]?.value ?? 0,
+    recent: {
+      total: recent.length,
+      wrongAnswer: tally(-1),
+      compileError: tally(-2),
+      runtimeError: tally(4, 3),
+      timeout: tally(1, 2),
+      runtimeErrorType: topType,
+    },
+  } satisfies MascotProfile)
+})