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/db/schema.ts

@@ -733,6 +733,8 @@ export const announcements = mysqlTable("announcements", {
   targetClassId: varchar("target_class_id", { length: 128 }),
   authorId: varchar("author_id", { length: 128 }).notNull().references(() => users.id),
   publishedAt: datetime("published_at", { mode: "date" }),
+  // V2-P2-13d: 公告置顶（置顶公告在列表中优先显示）
+  isPinned: boolean("is_pinned").default(false).notNull(),
   createdAt: timestamp("created_at", { mode: "date" }).defaultNow().notNull(),
   updatedAt: timestamp("updated_at", { mode: "date" }).defaultNow().onUpdateNow().notNull(),
 }, (table) => ({
@@ -741,6 +743,22 @@ export const announcements = mysqlTable("announcements", {
   typeIdx: index("announcements_type_idx").on(table.type),
   targetGradeIdx: index("announcements_target_grade_idx").on(table.targetGradeId),
   targetClassIdx: index("announcements_target_class_idx").on(table.targetClassId),
+  // V2-P2-13d: 置顶索引
+  statusPinnedIdx: index("announcements_status_pinned_idx").on(table.status, table.isPinned),
+}));
+
+// --- 8b. Announcement Reads (公告已读回执) ---
+
+export const announcementReads = mysqlTable("announcement_reads", {
+  id: id("id").primaryKey(),
+  announcementId: varchar("announcement_id", { length: 128 }).notNull().references(() => announcements.id, { onDelete: "cascade" }),
+  userId: varchar("user_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  readAt: timestamp("read_at", { mode: "date" }).defaultNow().notNull(),
+}, (table) => ({
+  announcementIdx: index("announcement_reads_announcement_idx").on(table.announcementId),
+  userIdx: index("announcement_reads_user_idx").on(table.userId),
+  // 唯一约束：一个用户对一条公告只能有一条已读记录
+  uniqueAnnouncementUser: uniqueIndex("announcement_reads_unique_idx").on(table.announcementId, table.userId),
 }));
 
 // --- 9. Audit & Login Logs ---
@@ -975,6 +993,8 @@ export const messages = mysqlTable("messages", {
   // 软删除：发送方/接收方各自独立删除，互不影响
   senderDeletedAt: timestamp("sender_deleted_at", { mode: "date" }),
   receiverDeletedAt: timestamp("receiver_deleted_at", { mode: "date" }),
+  // V2-P2-13c: 消息星标（接收方可标记重要消息）
+  isStarred: boolean("is_starred").default(false).notNull(),
   createdAt: timestamp("created_at", { mode: "date" }).defaultNow().notNull(),
 }, (table) => ({
   senderIdx: index("messages_sender_idx").on(table.senderId),
@@ -982,6 +1002,24 @@ export const messages = mysqlTable("messages", {
   isReadIdx: index("messages_is_read_idx").on(table.isRead),
   parentIdx: index("messages_parent_idx").on(table.parentMessageId),
   receiverReadIdx: index("messages_receiver_read_idx").on(table.receiverId, table.isRead),
+  // V2-P2-13c: 星标索引
+  receiverStarredIdx: index("messages_receiver_starred_idx").on(table.receiverId, table.isStarred),
+}));
+
+// --- 14b. Message Drafts (消息草稿) ---
+
+export const messageDrafts = mysqlTable("message_drafts", {
+  id: id("id").primaryKey(),
+  userId: varchar("user_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  receiverId: varchar("receiver_id", { length: 128 }).references(() => users.id, { onDelete: "cascade" }),
+  subject: varchar("subject", { length: 255 }),
+  content: text("content"),
+  parentMessageId: varchar("parent_message_id", { length: 128 }),
+  updatedAt: timestamp("updated_at", { mode: "date" }).defaultNow().onUpdateNow().notNull(),
+  createdAt: timestamp("created_at", { mode: "date" }).defaultNow().notNull(),
+}, (table) => ({
+  userIdx: index("message_drafts_user_idx").on(table.userId),
+  userUpdatedIdx: index("message_drafts_user_updated_idx").on(table.userId, table.updatedAt),
 }));
 
 // --- 15. Message Notifications (消息通知) ---
@@ -994,12 +1032,44 @@ export const messageNotifications = mysqlTable("message_notifications", {
   content: text("content"),
   link: varchar("link", { length: 512 }),
   isRead: boolean("is_read").default(false).notNull(),
+  // V2-P2-13b: 通知优先级（low/normal/high/urgent），默认 normal
+  priority: varchar("priority", { length: 16 }).default("normal").notNull(),
+  // V2-P2-13b: 通知归档标记，归档后不在默认列表显示
+  isArchived: boolean("is_archived").default(false).notNull(),
   createdAt: timestamp("created_at", { mode: "date" }).defaultNow().notNull(),
 }, (table) => ({
   userIdx: index("message_notifications_user_idx").on(table.userId),
   isReadIdx: index("message_notifications_is_read_idx").on(table.isRead),
   userReadIdx: index("message_notifications_user_read_idx").on(table.userId, table.isRead),
   createdAtIdx: index("message_notifications_created_at_idx").on(table.createdAt),
+  // V2-P2-13b: 新增优先级和归档索引
+  priorityIdx: index("message_notifications_priority_idx").on(table.priority),
+  userArchivedIdx: index("message_notifications_user_archived_idx").on(table.userId, table.isArchived),
+}));
+
+// --- 17. Notification Logs (通知发送日志) ---
+
+export const notificationLogs = mysqlTable("notification_logs", {
+  id: id("id").primaryKey(),
+  // 关联用户（通知接收人）
+  userId: varchar("user_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  // 通知标题（冗余存储，便于查询）
+  title: varchar("title", { length: 255 }).notNull(),
+  // 发送渠道: in_app | email | sms | wechat
+  channel: varchar("channel", { length: 32 }).notNull(),
+  // 发送状态: success | failure
+  status: varchar("status", { length: 16 }).notNull(),
+  // 渠道返回的消息 ID（用于追踪）
+  messageId: varchar("message_id", { length: 255 }),
+  // 失败时的错误信息
+  error: text("error"),
+  // 发送时间
+  sentAt: timestamp("sent_at", { mode: "date" }).defaultNow().notNull(),
+}, (table) => ({
+  userIdx: index("notification_logs_user_idx").on(table.userId),
+  channelIdx: index("notification_logs_channel_idx").on(table.channel),
+  statusIdx: index("notification_logs_status_idx").on(table.status),
+  sentAtIdx: index("notification_logs_sent_at_idx").on(table.sentAt),
 }));
 
 // --- 16. Notification Preferences (通知偏好) ---
@@ -1270,6 +1340,8 @@ export const learningDiagnosticReports = mysqlTable("learning_diagnostic_reports
   id: id("id").primaryKey(),
   studentId: varchar("student_id", { length: 128 }).references(() => users.id, { onDelete: "cascade" }),
   generatedBy: varchar("generated_by", { length: 128 }).references(() => users.id, { onDelete: "set null" }),
+  // v4-P1-4: 班级报告关联的 classId，用于发布时批量通知全班学生
+  classId: varchar("class_id", { length: 128 }).references(() => classes.id, { onDelete: "set null" }),
   reportType: diagnosticReportTypeEnum.default("individual").notNull(),
   period: varchar("period", { length: 50 }),
   summary: text("summary"),
@@ -1285,6 +1357,7 @@ export const learningDiagnosticReports = mysqlTable("learning_diagnostic_reports
   generatedByIdx: index("diagnostic_generated_by_idx").on(table.generatedBy),
   statusIdx: index("diagnostic_status_idx").on(table.status),
   reportTypeIdx: index("diagnostic_report_type_idx").on(table.reportType),
+  classIdx: index("diagnostic_class_idx").on(table.classId),
 }));
 
 // --- 24. Lesson Preparation (备课) ---
@@ -1440,3 +1513,30 @@ export const errorBookReviews = mysqlTable("error_book_reviews", {
   studentIdx: index("eb_review_student_idx").on(table.studentId),
   studentReviewedIdx: index("eb_review_student_reviewed_idx").on(table.studentId, table.reviewedAt),
 }));
+
+// --- 27. Grade Drafts (成绩录入草稿 - 服务端自动保存) ---
+
+/**
+ * 成绩录入草稿 - 用于跨设备恢复未保存的成绩。
+ * v3-P2-10: 替代纯 localStorage 方案，支持换设备恢复。
+ * 唯一键：userId + classId + subjectId + type，确保每位教师每组合只有一个草稿。
+ */
+export const gradeDrafts = mysqlTable("grade_drafts", {
+  id: id("id").primaryKey(),
+  userId: varchar("user_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  classId: varchar("class_id", { length: 128 }).notNull().references(() => classes.id, { onDelete: "cascade" }),
+  subjectId: varchar("subject_id", { length: 128 }).notNull().references(() => subjects.id, { onDelete: "cascade" }),
+  type: varchar("type", { length: 20 }).notNull(),
+  /** 草稿内容：{ scores: Record<string, string>, timestamp: number } */
+  content: json("content").notNull(),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().onUpdateNow().notNull(),
+}, (table) => ({
+  userDraftIdx: uniqueIndex("gd_user_class_subject_type_idx").on(
+    table.userId,
+    table.classId,
+    table.subjectId,
+    table.type
+  ),
+  userUpdatedIdx: index("gd_user_updated_idx").on(table.userId, table.updatedAt),
+}));