feat: 完成 P1 全部功能 + 修复 proxy 导出 + 切换 MySQL 端口至 14013

## P1 功能（20 项）
- 站内消息系统、家长仪表盘、学生考勤管理
- Excel 导入导出、用户批量导入、成绩导出
- 排课规则+自动排课+课表调整
- 成绩趋势+对比分析、密码安全策略、速率限制
- 数据变更日志、文件预览+存储策略、全文检索
- 依赖审计集成 CI、数据库定时备份、E2E 测试完善
- 通知偏好管理

## 基础设施修复
- src/proxy.ts: 将 middleware 导出重命名为 proxy（Next.js 16 要求）
- .env: MySQL 端口从 13002 切换至 14013
- scripts/create-db.ts: 新增数据库初始化脚本

## 架构文档同步
- 004_architecture_impact_map.md 和 005_architecture_data.json
  完整记录所有新增表、模块、路由、权限、依赖关系

src/modules/grades/data-access-ranking.ts

@@ -0,0 +1,121 @@
+import "server-only"
+
+import { and, asc, eq } from "drizzle-orm"
+
+import { db } from "@/shared/db"
+import {
+  classEnrollments,
+  gradeRecords,
+  users,
+} from "@/shared/db/schema"
+
+import type {
+  RankingTrendPoint,
+  RankingTrendResult,
+} from "./types"
+
+const toNumber = (v: unknown): number => {
+  const n = typeof v === "number" ? v : Number(v)
+  return Number.isFinite(n) ? n : 0
+}
+
+const normalize = (score: number, fullScore: number): number => {
+  if (fullScore <= 0) return 0
+  return Math.round((score / fullScore) * 10000) / 100
+}
+
+/**
+ * Get a student's ranking trend across assessments within their class.
+ * Each point represents one assessment (grouped by title), with the
+ * student's normalized score, rank, and total participants.
+ */
+export async function getRankingTrend(
+  studentId: string,
+  subjectId?: string,
+  semester?: "1" | "2"
+): Promise<RankingTrendResult | null> {
+  const [student] = await db
+    .select({ id: users.id, name: users.name })
+    .from(users)
+    .where(eq(users.id, studentId))
+    .limit(1)
+  if (!student) return null
+
+  const [enrollment] = await db
+    .select({ classId: classEnrollments.classId })
+    .from(classEnrollments)
+    .where(
+      and(
+        eq(classEnrollments.studentId, studentId),
+        eq(classEnrollments.status, "active")
+      )
+    )
+    .limit(1)
+
+  if (!enrollment) {
+    return {
+      studentId,
+      studentName: student.name ?? "Unknown",
+      points: [],
+    }
+  }
+
+  const conditions = [eq(gradeRecords.classId, enrollment.classId)]
+  if (subjectId) conditions.push(eq(gradeRecords.subjectId, subjectId))
+  if (semester) conditions.push(eq(gradeRecords.semester, semester))
+
+  const rows = await db
+    .select({
+      title: gradeRecords.title,
+      createdAt: gradeRecords.createdAt,
+      studentId: gradeRecords.studentId,
+      score: gradeRecords.score,
+      fullScore: gradeRecords.fullScore,
+    })
+    .from(gradeRecords)
+    .where(and(...conditions))
+    .orderBy(asc(gradeRecords.createdAt))
+
+  const byTitle = new Map<
+    string,
+    {
+      date: Date
+      entries: Array<{ studentId: string; normalized: number }>
+    }
+  >()
+
+  for (const r of rows) {
+    const entry = byTitle.get(r.title) ?? { date: r.createdAt, entries: [] }
+    entry.entries.push({
+      studentId: r.studentId,
+      normalized: normalize(toNumber(r.score), toNumber(r.fullScore)),
+    })
+    byTitle.set(r.title, entry)
+  }
+
+  const points: RankingTrendPoint[] = []
+  for (const [title, entry] of byTitle.entries()) {
+    if (entry.entries.length === 0) continue
+    const sorted = [...entry.entries].sort((a, b) => b.normalized - a.normalized)
+    const rank = sorted.findIndex((e) => e.studentId === studentId) + 1
+    if (rank <= 0) continue
+    const studentEntry = sorted.find((e) => e.studentId === studentId)
+    if (!studentEntry) continue
+
+    points.push({
+      title,
+      date: entry.date.toISOString(),
+      score: studentEntry.normalized,
+      rank,
+      totalStudents: sorted.length,
+    })
+  }
+
+  points.sort((a, b) => new Date(a.date).getTime() - new Date(b.date).getTime())
+
+  return {
+    studentId,
+    studentName: student.name ?? "Unknown",
+    points,
+  }
+}