feat(announcements,messaging,notifications): 实现所有长期问题 — SSE 实时推送 + 通知日志持久化 + 优先级/归档 + 消息星标/草稿 + 公告已读回执/置顶 + 分类筛选/桌面推送 + 测试覆盖

P1-8 通知实时推送（SSE）:
- 新增 /api/notifications/stream SSE 端点（15 秒推送，5 分钟超时）
- 新增 useNotificationStream Hook（SSE + 轮询降级）
- NotificationDropdown 改用 SSE 实时推送

P2-12 测试覆盖:
- notifications/dispatcher.test.ts（6 个测试，渠道选择逻辑）
- notifications/channels/in-app-channel.test.ts（9 个测试，类型映射）
- messaging/schema.test.ts（34 个测试，Zod 校验）
- tests/e2e/messages.spec.ts（消息模块 E2E 测试）
- vitest.unit.config.ts 添加 server-only stub

P2-13a 通知发送日志持久化:
- 新增 notification_logs 表（userId/title/channel/status/messageId/error/sentAt）
- logNotificationSend 改为 async 写入 DB（失败降级 console）
- dispatcher 传递 payload 用于持久化

P2-13b 通知优先级和归档:
- messageNotifications 表新增 priority（low/normal/high/urgent）和 isArchived 字段
- getNotifications 支持归档和优先级筛选
- 新增 archiveNotificationAction
- NotificationList 显示优先级 Badge 和归档按钮

P2-13c 消息星标和草稿:
- messages 表新增 isStarred 字段
- 新增 message_drafts 表
- 新增 toggleMessageStar + 草稿 CRUD Server Actions
- 新增 5 个草稿 data-access 函数

P2-13d 公告已读回执和置顶:
- announcements 表新增 isPinned 字段
- 新增 announcement_reads 表（唯一索引保证幂等）
- 新增 toggleAnnouncementPinAction + markAnnouncementAsReadAction
- getAnnouncements 排序置顶优先

P2-13e 通知分类筛选和桌面推送:
- NotificationList 添加按类型筛选按钮组
- 新增 useDesktopNotifications Hook（浏览器 Notification API）
- NotificationDropdown 集成桌面推送（新通知触发）

架构图同步:
- 004 和 005 均已更新（新增表、Action、Hook、组件描述）

src/shared/i18n/messages/en/announcements.json

@@ -21,7 +21,10 @@
   "status": {
     "draft": "Draft",
     "published": "Published",
-    "archived": "Archived"
+    "archived": "Archived",
+    "pinned": "Pinned",
+    "read": "Read",
+    "unread": "Unread"
   },
   "type": {
     "school": "School",
@@ -52,7 +55,10 @@
     "archive": "Archive",
     "edit": "Edit",
     "delete": "Delete",
-    "back": "Back"
+    "back": "Back",
+    "pin": "Pin",
+    "unpin": "Unpin",
+    "markRead": "Mark as Read"
   },
   "messages": {
     "created": "Announcement created",
@@ -67,7 +73,9 @@
     "archiveFailed": "Failed to archive",
     "deleteFailed": "Failed to delete",
     "invalidForm": "Invalid form data",
-    "invalidState": "Invalid form state"
+    "invalidState": "Invalid state",
+    "pinToggled": "Pin status updated",
+    "markedRead": "Marked as read"
   },
   "meta": {
     "publishedAt": "Published {date}",

src/shared/i18n/messages/en/messages.json

@@ -21,7 +21,11 @@
     "send": "Send",
     "sending": "Sending...",
     "cancel": "Cancel",
-    "back": "Back"
+    "back": "Back",
+    "star": "Star",
+    "unstar": "Unstar",
+    "saveDraft": "Save Draft",
+    "deleteDraft": "Delete Draft"
   },
   "form": {
     "to": "To",
@@ -55,7 +59,9 @@
     "sentEmpty": "No sent messages",
     "sentEmptyDesc": "You have not sent any messages yet.",
     "deleteTitle": "Delete message",
-    "deleteDesc": "This will permanently delete the message \"{subject}\"."
+    "deleteDesc": "This will permanently delete the message \"{subject}\".",
+    "noDrafts": "No drafts",
+    "noStarred": "No starred messages"
   },
   "messages": {
     "sent": "Message sent",
@@ -66,7 +72,10 @@
     "deleteFailed": "Failed to delete",
     "notFound": "Message not found",
     "invalidId": "Invalid message id",
-    "selectRecipient": "Please select a recipient"
+    "selectRecipient": "Please select a recipient",
+    "draftSaved": "Draft saved",
+    "draftDeleted": "Draft deleted",
+    "starToggled": "Star status updated"
   },
   "notification": {
     "messageTitle": "New message: {subject}",

src/shared/i18n/messages/en/notifications.json

@@ -10,7 +10,9 @@
     "markRead": "Mark as read",
     "markAllRead": "Mark all as read",
     "viewAll": "View all notifications",
-    "view": "View"
+    "view": "View",
+    "archive": "Archive",
+    "unarchive": "Unarchive"
   },
   "type": {
     "message": "Message",
@@ -18,18 +20,30 @@
     "homework": "Homework",
     "grade": "Grade"
   },
+  "filter": {
+    "all": "All"
+  },
+  "priority": {
+    "low": "Low",
+    "normal": "Normal",
+    "high": "High",
+    "urgent": "Urgent"
+  },
   "status": {
     "new": "New"
   },
   "empty": {
     "noNotifications": "No notifications",
     "noNotificationsDesc": "You have no notifications yet.",
-    "noNotificationsDropdown": "No notifications"
+    "noNotificationsDropdown": "No notifications",
+    "noFilterResults": "No results",
+    "noFilterResultsDesc": "No notifications match the current filter."
   },
   "messages": {
     "allMarkedRead": "All notifications marked as read",
     "notificationMarkedRead": "Notification marked as read",
-    "markReadFailed": "Failed to mark as read"
+    "markReadFailed": "Failed to mark as read",
+    "archiveFailed": "Archive failed"
   },
   "error": {
     "loadFailed": "Failed to load notifications",

src/shared/i18n/messages/zh-CN/announcements.json

@@ -21,7 +21,10 @@
   "status": {
     "draft": "草稿",
     "published": "已发布",
-    "archived": "已归档"
+    "archived": "已归档",
+    "pinned": "已置顶",
+    "read": "已读",
+    "unread": "未读"
   },
   "type": {
     "school": "全校",
@@ -52,7 +55,10 @@
     "archive": "归档",
     "edit": "编辑",
     "delete": "删除",
-    "back": "返回"
+    "back": "返回",
+    "pin": "置顶",
+    "unpin": "取消置顶",
+    "markRead": "标记已读"
   },
   "messages": {
     "created": "公告已创建",
@@ -67,7 +73,9 @@
     "archiveFailed": "归档失败",
     "deleteFailed": "删除失败",
     "invalidForm": "表单数据无效",
-    "invalidState": "表单状态无效"
+    "invalidState": "表单状态无效",
+    "pinToggled": "置顶状态已更新",
+    "markedRead": "已标记为已读"
   },
   "meta": {
     "publishedAt": "发布于 {date}",

src/shared/i18n/messages/zh-CN/messages.json

@@ -21,7 +21,11 @@
     "send": "发送",
     "sending": "发送中...",
     "cancel": "取消",
-    "back": "返回"
+    "back": "返回",
+    "star": "星标",
+    "unstar": "取消星标",
+    "saveDraft": "保存草稿",
+    "deleteDraft": "删除草稿"
   },
   "form": {
     "to": "收件人",
@@ -55,7 +59,9 @@
     "sentEmpty": "无已发送消息",
     "sentEmptyDesc": "您还没有发送任何消息。",
     "deleteTitle": "删除消息",
-    "deleteDesc": "此操作将永久删除消息{subject}。"
+    "deleteDesc": "此操作将永久删除消息{subject}。",
+    "noDrafts": "暂无草稿",
+    "noStarred": "暂无星标消息"
   },
   "messages": {
     "sent": "消息已发送",
@@ -66,7 +72,10 @@
     "deleteFailed": "删除失败",
     "notFound": "消息不存在",
     "invalidId": "消息 ID 无效",
-    "selectRecipient": "请选择收件人"
+    "selectRecipient": "请选择收件人",
+    "draftSaved": "草稿已保存",
+    "draftDeleted": "草稿已删除",
+    "starToggled": "星标状态已更新"
   },
   "notification": {
     "messageTitle": "新消息：{subject}",

src/shared/i18n/messages/zh-CN/notifications.json

@@ -10,7 +10,9 @@
     "markRead": "标记已读",
     "markAllRead": "全部标记已读",
     "viewAll": "查看全部通知",
-    "view": "查看"
+    "view": "查看",
+    "archive": "归档",
+    "unarchive": "取消归档"
   },
   "type": {
     "message": "消息",
@@ -18,18 +20,30 @@
     "homework": "作业",
     "grade": "成绩"
   },
+  "filter": {
+    "all": "全部"
+  },
+  "priority": {
+    "low": "低",
+    "normal": "普通",
+    "high": "高",
+    "urgent": "紧急"
+  },
   "status": {
     "new": "新"
   },
   "empty": {
     "noNotifications": "暂无通知",
     "noNotificationsDesc": "您还没有任何通知。",
-    "noNotificationsDropdown": "暂无通知"
+    "noNotificationsDropdown": "暂无通知",
+    "noFilterResults": "无筛选结果",
+    "noFilterResultsDesc": "当前筛选条件下没有通知。"
   },
   "messages": {
     "allMarkedRead": "全部已标记为已读",
     "notificationMarkedRead": "通知已标记为已读",
-    "markReadFailed": "标记已读失败"
+    "markReadFailed": "标记已读失败",
+    "archiveFailed": "归档失败"
   },
   "error": {
     "loadFailed": "通知加载失败",