feat(portal-shell): extract gql documents to operations layer

M1 Task 3: 从 31 widget 抽取 51 个 gql 文档到 7 个 operations 文件

- universal(7) + sidebar(3) + topbar(3) + teacher(6) + student(8) + parent(4) + admin(20) = 51 DOC

- operations/index.ts barrel 统一出口

- codegen.yml 启用 documents + skipDocumentsValidation（services 子图字段待补齐）

- 生成 types.ts (28KB) + operations.ts (10KB)

apps/portal-shell/src/lib/api/operations/universal.graphql.ts

@@ -0,0 +1,93 @@
+// Universal domain GraphQL documents
+// Extracted from widgets/universal/*/index.tsx
+// Related: spec section 2.2
+import { gql } from "@apollo/client";
+
+// From widgets/universal/grades-widget
+export const GET_GRADES_DOC = gql`
+  query GetGrades($classId: ID!) {
+    grades(classId: $classId) {
+      studentId
+      score
+    }
+  }
+`;
+
+// From widgets/universal/homework-widget
+export const GET_HOMEWORKS_DOC = gql`
+  query GetHomeworks($classId: ID!, $limit: Int) {
+    homeworks(classId: $classId, limit: $limit) {
+      id
+      title
+      dueDate
+      status
+    }
+  }
+`;
+
+// From widgets/universal/schedule-widget
+export const GET_SCHEDULE_DOC = gql`
+  query GetSchedule($classId: ID!, $dayOfWeek: Int) {
+    schedule(classId: $classId, dayOfWeek: $dayOfWeek) {
+      id
+      subject
+      startTime
+      endTime
+      teacherName
+    }
+  }
+`;
+
+// From widgets/universal/attendance-widget
+export const GET_ATTENDANCE_DOC = gql`
+  query GetAttendance($classId: ID!, $termId: ID!) {
+    attendance(classId: $classId, termId: $termId) {
+      present
+      absent
+      late
+      total
+    }
+  }
+`;
+
+// From widgets/universal/exams-widget
+export const GET_EXAMS_DOC = gql`
+  query GetExams($classId: ID!, $limit: Int) {
+    exams(classId: $classId, limit: $limit) {
+      id
+      name
+      examDate
+      subject
+      maxScore
+    }
+  }
+`;
+
+// From widgets/universal/notifications-widget
+export const GET_NOTIFICATIONS_LIST_DOC = gql`
+  query GetNotificationsList($limit: Int, $offset: Int) {
+    notifications(limit: $limit, offset: $offset) {
+      items {
+        id
+        title
+        body
+        createdAt
+        type
+      }
+      total
+    }
+  }
+`;
+
+// From widgets/universal/announcements-widget
+export const GET_ANNOUNCEMENTS_DOC = gql`
+  query GetAnnouncements($limit: Int) {
+    announcements(limit: $limit) {
+      id
+      title
+      body
+      author
+      publishedAt
+    }
+  }
+`;