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/announcements/schema.ts

@@ -0,0 +1,45 @@
+import { z } from "zod"
+
+export const CreateAnnouncementSchema = z
+  .object({
+    title: z.string().trim().min(1).max(255),
+    content: z.string().trim().min(1),
+    type: z.enum(["school", "grade", "class"]).optional(),
+    status: z.enum(["draft", "published", "archived"]).optional(),
+    targetGradeId: z.string().trim().optional().nullable(),
+    targetClassId: z.string().trim().optional().nullable(),
+    publishedAt: z.string().optional().nullable(),
+  })
+  .transform((v) => ({
+    title: v.title,
+    content: v.content,
+    type: v.type ?? "school",
+    status: v.status ?? "draft",
+    targetGradeId: v.targetGradeId && v.targetGradeId.length > 0 ? v.targetGradeId : null,
+    targetClassId: v.targetClassId && v.targetClassId.length > 0 ? v.targetClassId : null,
+    publishedAt: v.publishedAt && v.publishedAt.length > 0 ? v.publishedAt : null,
+  }))
+
+export type CreateAnnouncementInput = z.infer<typeof CreateAnnouncementSchema>
+
+export const UpdateAnnouncementSchema = z
+  .object({
+    title: z.string().trim().min(1).max(255),
+    content: z.string().trim().min(1),
+    type: z.enum(["school", "grade", "class"]).optional(),
+    status: z.enum(["draft", "published", "archived"]).optional(),
+    targetGradeId: z.string().trim().optional().nullable(),
+    targetClassId: z.string().trim().optional().nullable(),
+    publishedAt: z.string().optional().nullable(),
+  })
+  .transform((v) => ({
+    title: v.title,
+    content: v.content,
+    type: v.type ?? "school",
+    status: v.status ?? "draft",
+    targetGradeId: v.targetGradeId && v.targetGradeId.length > 0 ? v.targetGradeId : null,
+    targetClassId: v.targetClassId && v.targetClassId.length > 0 ? v.targetClassId : null,
+    publishedAt: v.publishedAt && v.publishedAt.length > 0 ? v.publishedAt : null,
+  }))
+
+export type UpdateAnnouncementInput = z.infer<typeof UpdateAnnouncementSchema>