refactor: fix all P0/P1/P2 bugs and architecture issues

Bug fixes (from bugs/ directory):

- Fix cross-module DB queries in 9 modules (homework, grades, parent, diagnostic, elective, proctoring, notifications, scheduling, classes) by routing through data-access functions

- Fix shared/lib <-> auth circular dependency via new session.ts module

- Fix divide-by-zero guard in grades data-access

- Fix audit export data truncation (paginated fetch for full datasets)

- Fix missing transactions in homework grading and elective lottery

- Fix missing revalidatePath in course-plans actions

- Fix frontend permission checks using requirePermission instead of requireAuth

- Fix dashboard role routing using session.user.roles

- Fix student auth pattern (migrate getDemoStudentUser to users module)

- Fix ActionState return type handling in components

Code quality fixes:

- Remove 60+ as type assertions (replace with type guards)

- Remove non-null assertions (use optional chaining or explicit checks)

- Convert dynamic imports to static imports (grades, diagnostic)

- Add React.cache() wrapping for read functions

- Parallelize independent queries with Promise.all

- Add explicit return types to 30+ arrow functions

- Replace any with unknown + type guards

- Fix import type for type-only imports

- Add Zod validation schemas for classes and diagnostic modules

- Extract duplicate code (normalizeRoleName, normalizeBcryptHash, logger IP extraction)

- Add console.error to silent catch blocks

- Fix permission naming consistency (exam:proctor_read -> exam:proctor:read)

Architecture doc sync:

- Update 004_architecture_impact_map.md and 005_architecture_data.json

- Update management-modules-audit.md for P0-7 cross-module fix

Moved deleted proctoring event route to deletes/ folder.

src/modules/notifications/index.ts

@@ -3,7 +3,9 @@
  *
  * 对外导出:
  * - sendNotification / sendBatchNotifications: 分发器入口
- * - 类型定义: NotificationPayload, ChannelSendResult, NotificationChannel 等
+ * - createNotification / getNotifications / markNotificationAsRead / markAllNotificationsAsRead / getUnreadNotificationCount: 站内通知 CRUD
+ * - getNotificationPreferences / upsertNotificationPreferences: 通知偏好 CRUD
+ * - 类型定义: NotificationPayload, ChannelSendResult, NotificationChannel, NotificationType, Notification, NotificationPreferences 等
  * - 渠道发送器工厂: createSmsSender, createWechatSender, createEmailSender, createInAppSender
  *
  * 典型用法:
@@ -20,6 +22,20 @@
  */
 
 export { sendNotification, sendBatchNotifications } from "./dispatcher"
+export {
+  createNotification,
+  getNotifications,
+  markNotificationAsRead,
+  markAllNotificationsAsRead,
+  getUnreadNotificationCount,
+  getUserContactInfo,
+  logNotificationSend,
+  logNotificationSendBatch,
+} from "./data-access"
+export {
+  getNotificationPreferences,
+  upsertNotificationPreferences,
+} from "./preferences"
 export type {
   NotificationChannel,
   NotificationPayload,
@@ -28,6 +44,13 @@ export type {
   SmsChannelConfig,
   WechatChannelConfig,
   EmailChannelConfig,
+  NotificationType,
+  Notification,
+  PaginatedResult,
+  GetNotificationsParams,
+  CreateNotificationInput,
+  NotificationPreferences,
+  UpdateNotificationPreferencesInput,
 } from "./types"
 export type { NotificationChannelSender, ChannelRecipient } from "./channels/types"