feat(announcements,messaging): 公告与消息模块审计重构 — i18n + Error Boundary + a11y

- 新增审计报告 docs/architecture/audit/announcements-messages-audit-report.md
- 新增中英双语 i18n 字典 announcements.json / messages.json（11/13 个命名空间）
- 重构所有 announcements 和 messaging 组件接入 next-intl（useTranslations）
- 所有页面 page.tsx 使用 generateMetadata + getTranslations 替代硬编码 metadata
- 新增 7 个 error.tsx 错误边界（4 公告 + 3 消息），统一 EmptyState + i18n + 重试
- a11y 改进：announcement-card / message-list / notification-dropdown 添加 aria-label
- 同步架构图 004 和 005：i18n.messages 清单 + 已知问题修复记录

src/modules/messaging/components/message-detail.tsx

@@ -4,21 +4,13 @@ import { useState } from "react"
 import Link from "next/link"
 import { useRouter } from "next/navigation"
 import { toast } from "sonner"
+import { useTranslations } from "next-intl"
 import { ArrowLeft, Mail, Reply, Trash2 } from "lucide-react"
 
 import { Badge } from "@/shared/components/ui/badge"
 import { Button } from "@/shared/components/ui/button"
 import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
-import {
-  AlertDialog,
-  AlertDialogAction,
-  AlertDialogCancel,
-  AlertDialogContent,
-  AlertDialogDescription,
-  AlertDialogFooter,
-  AlertDialogHeader,
-  AlertDialogTitle,
-} from "@/shared/components/ui/alert-dialog"
+import { ConfirmDeleteDialog } from "@/shared/components/ui/confirm-delete-dialog"
 import { formatDate } from "@/shared/lib/utils"
 import { usePermission } from "@/shared/hooks/use-permission"
 import { Permissions } from "@/shared/types/permissions"
@@ -35,6 +27,7 @@ export function MessageDetail({
   currentUserId: string
   backHref?: string
 }) {
+  const t = useTranslations("messages")
   const router = useRouter()
   const [isWorking, setIsWorking] = useState(false)
   const [deleteOpen, setDeleteOpen] = useState(false)
@@ -44,7 +37,7 @@ export function MessageDetail({
 
   const isReceived = message.receiverId === currentUserId
   const counterpart = isReceived ? message.senderName : message.receiverName
-  const counterpartLabel = isReceived ? "From" : "To"
+  const counterpartLabel = isReceived ? t("meta.from") : t("meta.to")
 
   const handleDelete = async () => {
     setIsWorking(true)
@@ -55,10 +48,10 @@ export function MessageDetail({
         router.push("/messages")
         router.refresh()
       } else {
-        toast.error(res.message || "Failed to delete")
+        toast.error(res.message || t("messages.deleteFailed"))
       }
     } catch {
-      toast.error("Failed to delete")
+      toast.error(t("messages.deleteFailed"))
     } finally {
       setIsWorking(false)
       setDeleteOpen(false)
@@ -75,26 +68,26 @@ export function MessageDetail({
     <div className="space-y-6">
       <div className="flex items-center justify-between gap-2">
         <div className="flex items-center gap-2">
-          <Button asChild variant="ghost" size="icon">
+          <Button asChild variant="ghost" size="icon" aria-label={t("actions.back")}>
             <Link href={backHref}>
               <ArrowLeft className="h-4 w-4" />
             </Link>
           </Button>
-          <h2 className="text-2xl font-bold tracking-tight">Message</h2>
+          <h2 className="text-2xl font-bold tracking-tight">{t("title.detail")}</h2>
         </div>
         <div className="flex flex-wrap items-center gap-2">
           {canSend ? (
             <Button asChild variant="outline">
               <Link href={replyHref ?? "#"}>
                 <Reply className="mr-2 h-4 w-4" />
-                Reply
+                {t("actions.reply")}
               </Link>
             </Button>
           ) : null}
           {canDelete ? (
             <Button onClick={() => setDeleteOpen(true)} disabled={isWorking} variant="destructive">
               <Trash2 className="mr-2 h-4 w-4" />
-              Delete
+              {t("actions.delete")}
             </Button>
           ) : null}
         </div>
@@ -103,26 +96,26 @@ export function MessageDetail({
       <Card>
         <CardHeader className="space-y-2">
           <div className="flex flex-wrap items-center gap-2">
-            <Mail className="text-muted-foreground h-4 w-4" />
+            <Mail className="text-muted-foreground h-4 w-4" aria-hidden="true" />
             {isReceived && !message.isRead ? (
-              <Badge variant="default">New</Badge>
+              <Badge variant="default">{t("status.new")}</Badge>
             ) : isReceived ? (
-              <Badge variant="secondary">Read</Badge>
+              <Badge variant="secondary">{t("status.read")}</Badge>
             ) : (
-              <Badge variant="outline">Sent</Badge>
+              <Badge variant="outline">{t("status.sent")}</Badge>
             )}
           </div>
-          <CardTitle className="text-2xl">{message.subject ?? "(no subject)"}</CardTitle>
+          <CardTitle className="text-2xl">{message.subject ?? t("meta.noSubject")}</CardTitle>
           <div className="flex flex-wrap items-center gap-2 text-xs text-muted-foreground">
             <span>
-              {counterpartLabel}: <span className="font-medium">{counterpart ?? "Unknown"}</span>
+              {counterpartLabel}: <span className="font-medium">{counterpart ?? t("meta.unknown")}</span>
             </span>
             <span>·</span>
             <span>{formatDate(message.createdAt)}</span>
             {message.readAt && isReceived ? (
               <>
                 <span>·</span>
-                <span>Read {formatDate(message.readAt)}</span>
+                <span>{t("meta.readAt", { date: formatDate(message.readAt) })}</span>
               </>
             ) : null}
           </div>
@@ -132,22 +125,14 @@ export function MessageDetail({
         </CardContent>
       </Card>
 
-      <AlertDialog open={deleteOpen} onOpenChange={setDeleteOpen}>
-        <AlertDialogContent>
-          <AlertDialogHeader>
-            <AlertDialogTitle>Delete message</AlertDialogTitle>
-            <AlertDialogDescription>
-              This will permanently delete the message &quot;{message.subject ?? "(no subject)"}&quot;.
-            </AlertDialogDescription>
-          </AlertDialogHeader>
-          <AlertDialogFooter>
-            <AlertDialogCancel disabled={isWorking}>Cancel</AlertDialogCancel>
-            <AlertDialogAction onClick={handleDelete} disabled={isWorking}>
-              Delete
-            </AlertDialogAction>
-          </AlertDialogFooter>
-        </AlertDialogContent>
-      </AlertDialog>
+      <ConfirmDeleteDialog
+        open={deleteOpen}
+        onOpenChange={setDeleteOpen}
+        title={t("empty.deleteTitle")}
+        description={t("empty.deleteDesc", { subject: message.subject ?? t("meta.noSubject") })}
+        onConfirm={handleDelete}
+        isWorking={isWorking}
+      />
     </div>
   )
 }