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

tests/e2e/navigation.spec.ts

@@ -0,0 +1,108 @@
+import { expect, test } from "@playwright/test"
+
+/**
+ * 导航测试：验证各角色的导航链接不会返回 404。
+ * 需要数据库环境以完成登录流程；未配置 DATABASE_URL 时自动跳过。
+ */
+
+const ADMIN_EMAIL = process.env.E2E_ADMIN_EMAIL ?? "admin@e2e.local"
+const ADMIN_PASSWORD = process.env.E2E_ADMIN_PASSWORD ?? "e2e-pass-123456"
+const TEACHER_EMAIL = process.env.E2E_TEACHER_EMAIL ?? "teacher@e2e.local"
+const TEACHER_PASSWORD = process.env.E2E_TEACHER_PASSWORD ?? "e2e-pass-123456"
+const STUDENT_EMAIL = process.env.E2E_STUDENT_EMAIL ?? "student@e2e.local"
+const STUDENT_PASSWORD = process.env.E2E_STUDENT_PASSWORD ?? "e2e-pass-123456"
+
+const ADMIN_NAV_HREFS = [
+  "/admin/dashboard",
+  "/admin/school",
+  "/admin/school/schools",
+  "/admin/school/grades",
+  "/admin/school/grades/insights",
+  "/admin/school/departments",
+  "/admin/school/classes",
+  "/admin/school/academic-year",
+  "/admin/audit-logs",
+  "/admin/audit-logs/login-logs",
+  "/admin/announcements",
+  "/messages",
+  "/settings",
+]
+
+const TEACHER_NAV_HREFS = [
+  "/teacher/dashboard",
+  "/teacher/textbooks",
+  "/teacher/exams",
+  "/teacher/exams/all",
+  "/teacher/homework",
+  "/teacher/homework/assignments",
+  "/teacher/homework/submissions",
+  "/teacher/grades",
+  "/teacher/grades/entry",
+  "/teacher/grades/stats",
+  "/teacher/grades/analytics",
+  "/teacher/questions",
+  "/teacher/classes",
+  "/teacher/classes/my",
+  "/teacher/classes/students",
+  "/teacher/classes/schedule",
+  "/teacher/course-plans",
+  "/teacher/attendance",
+  "/teacher/attendance/sheet",
+  "/teacher/attendance/stats",
+  "/teacher/schedule-changes",
+  "/announcements",
+  "/messages",
+]
+
+const STUDENT_NAV_HREFS = [
+  "/student/dashboard",
+  "/student/learning/courses",
+  "/student/learning/assignments",
+  "/student/learning/textbooks",
+  "/student/schedule",
+  "/student/grades",
+  "/student/attendance",
+  "/announcements",
+  "/messages",
+]
+
+async function login(page: import("@playwright/test").Page, email: string, password: string) {
+  await page.goto("/login")
+  await page.getByLabel("Email").fill(email)
+  await page.getByLabel("Password").fill(password)
+  await page.getByRole("button", { name: "Sign In with Email" }).click()
+}
+
+test.describe("Navigation", () => {
+  test.skip(!process.env.DATABASE_URL, "requires DATABASE_URL for authenticated navigation")
+
+  test("should not have 404 links in admin nav", async ({ page }) => {
+    await login(page, ADMIN_EMAIL, ADMIN_PASSWORD)
+    for (const href of ADMIN_NAV_HREFS) {
+      const response = await page.goto(href)
+      const status = response?.status() ?? 200
+      expect(status, `admin nav ${href} returned ${status}`).toBeLessThan(400)
+      await expect(page).not.toHaveURL(/\/login(?:$|[/?#])/)
+    }
+  })
+
+  test("should not have 404 links in teacher nav", async ({ page }) => {
+    await login(page, TEACHER_EMAIL, TEACHER_PASSWORD)
+    for (const href of TEACHER_NAV_HREFS) {
+      const response = await page.goto(href)
+      const status = response?.status() ?? 200
+      expect(status, `teacher nav ${href} returned ${status}`).toBeLessThan(400)
+      await expect(page).not.toHaveURL(/\/login(?:$|[/?#])/)
+    }
+  })
+
+  test("should not have 404 links in student nav", async ({ page }) => {
+    await login(page, STUDENT_EMAIL, STUDENT_PASSWORD)
+    for (const href of STUDENT_NAV_HREFS) {
+      const response = await page.goto(href)
+      const status = response?.status() ?? 200
+      expect(status, `student nav ${href} returned ${status}`).toBeLessThan(400)
+      await expect(page).not.toHaveURL(/\/login(?:$|[/?#])/)
+    }
+  })
+})