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/components/announcement-card.tsx

@@ -0,0 +1,79 @@
+"use client"
+
+import Link from "next/link"
+import { useMemo } from "react"
+import { Badge } from "@/shared/components/ui/badge"
+import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
+import { formatDate } from "@/shared/lib/utils"
+import type { Announcement } from "../types"
+
+const STATUS_LABEL: Record<Announcement["status"], string> = {
+  draft: "Draft",
+  published: "Published",
+  archived: "Archived",
+}
+
+const STATUS_VARIANT: Record<
+  Announcement["status"],
+  "default" | "secondary" | "outline"
+> = {
+  draft: "secondary",
+  published: "default",
+  archived: "outline",
+}
+
+const TYPE_LABEL: Record<Announcement["type"], string> = {
+  school: "School",
+  grade: "Grade",
+  class: "Class",
+}
+
+export function AnnouncementCard({
+  announcement,
+  href,
+}: {
+  announcement: Announcement
+  href?: string
+}) {
+  const card = useMemo(
+    () => (
+      <Card className="h-full transition-colors hover:bg-accent/50">
+        <CardHeader className="flex flex-row items-start justify-between gap-2 space-y-0">
+          <CardTitle className="line-clamp-2 text-base">{announcement.title}</CardTitle>
+          <Badge variant={STATUS_VARIANT[announcement.status]} className="shrink-0">
+            {STATUS_LABEL[announcement.status]}
+          </Badge>
+        </CardHeader>
+        <CardContent className="space-y-2">
+          <p className="line-clamp-3 text-sm text-muted-foreground whitespace-pre-wrap">
+            {announcement.content}
+          </p>
+          <div className="flex flex-wrap items-center gap-2 text-xs text-muted-foreground">
+            <Badge variant="outline" className="capitalize">
+              {TYPE_LABEL[announcement.type]}
+            </Badge>
+            <span>
+              {announcement.publishedAt
+                ? `Published ${formatDate(announcement.publishedAt)}`
+                : `Updated ${formatDate(announcement.updatedAt)}`}
+            </span>
+            {announcement.authorName ? (
+              <span className="ml-auto">by {announcement.authorName}</span>
+            ) : null}
+          </div>
+        </CardContent>
+      </Card>
+    ),
+    [announcement]
+  )
+
+  if (href) {
+    return (
+      <Link href={href} className="block h-full">
+        {card}
+      </Link>
+    )
+  }
+
+  return card
+}