feat(portal-shell): course-plans + elective 模块 5 页迁移（教师域 §9.1 B2）

§9.1 line 635-636 教师域：
- /shell/teacher/course-plans (列表) + /[id] (详情) — 2 页
- /shell/teacher/elective (列表) + /create (表单) + /[id]/edit (编辑表单) — 3 页
契约：全 ❌ schema 无 → MSW 兜底 + @contract-pending

新增文件：
- src/lib/api/{course-plans,elective}.ts (8 hooks 合计)
- src/lib/api/operations/{course-plans,elective}.graphql.ts (8 documents)
- src/features/teacher/{course-plans,elective}/ (clients + transformations + tests)
- src/app/shell/teacher/{course-plans,elective}/ (5 page.tsx + 2 loading + 2 error)

修改文件：
- src/mocks/graphql-data.ts (3 mock 数据 + 8 handler cases)
- src/messages/{zh-CN,en}.json (coursePlans/elective i18n 命名空间)
- src/lib/api/{index,operations/index}.ts (导出 course-plans/elective)
- src/shared/lib/route-permissions.ts (2 EXACT + 2 PREFIX 条目)
- scripts/check-page-count.ts (baseline 48 → 53)

DoD 验收（§11.3 11 项）：
- typecheck 0 errors
- lint 0 errors
- vitest 645 tests passed
- lint:tokens 0 errors
- check:pages 53 PASS
- route-permissions 已声明
- 三态齐备
- @contract-pending + MSW 兜底
- i18n zh-CN + en 同步

设计决策：
- COURSE_PLAN_* 权限点不存在于 PERMISSION_BITMAP_ORDER，复用 LESSON_PLAN_READ/CREATE/UPDATE（同备课域语义对齐）
- elective 使用已存在的 ELECTIVE_READ/ELECTIVE_MANAGE
- 编辑表单用 useEffect + initialized state guard 预填数据

关联：ARCHITECTURE.md §5.3 / §5.4 / §9.1 / §10 P2 / §11.3 / §11.4
契约工单：docs/architecture/issues/contracts/core-edu_contract.md

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

@@ -0,0 +1,84 @@
+// Elective domain GraphQL documents (ARCHITECTURE.md §5.3 契约纪律 / §9.1)
+//
+// 拆分原则：
+// - 全部操作：❌ schema 无 electives / elective(id) 根字段，也无 Mutation 类型
+//     → 走 MSW 兜底（@contract-pending），等待后端补齐契约
+//
+// 契约工单：docs/architecture/issues/contracts/core-edu_contract.md#elective
+// 关联：ARCHITECTURE.md §5.3 / §5.4 / §9.1 / §11.4
+import { gql } from "@apollo/client";
+
+// ── 假契约查询（@contract-pending）─────────────────────────────
+// 列表查询：schema 无 electives(...) 根字段
+// 页面通过 MSW 兜底获取列表数据，后端补齐后切换 fetcher 指向真实查询
+// 契约工单：core-edu_contract.md#electives-list
+export const GET_ELECTIVES_DOC = gql`
+  query GetElectives($status: String, $q: String, $limit: Int, $offset: Int) {
+    electives(status: $status, q: $q, limit: $limit, offset: $offset) {
+      items {
+        id
+        name
+        description
+        capacity
+        enrolledCount
+        semester
+        gradeLevel
+        subject
+        teacherId
+        teacherName
+        status
+        createdAt
+        updatedAt
+      }
+      total
+    }
+  }
+`;
+
+// ── 单查（@contract-pending）────────────────────────────────────
+// schema 无 elective(id) 根字段 → MSW 兜底
+// 用于 /shell/teacher/elective/[id]/edit 编辑表单页预填
+// 契约工单：core-edu_contract.md#elective-by-id
+export const GET_ELECTIVE_DOC = gql`
+  query GetElective($id: ID!) {
+    elective(id: $id) {
+      id
+      name
+      description
+      capacity
+      enrolledCount
+      semester
+      gradeLevel
+      subject
+      teacherId
+      teacherName
+      status
+      createdAt
+      updatedAt
+    }
+  }
+`;
+
+// ── 假契约变更（@contract-pending）─────────────────────────────
+// 创建选修课：schema 无 Mutation 类型
+// 页面通过 MSW 兜底提交，后端补齐 mutation 后切换 fetcher
+// 契约工单：core-edu_contract.md#create-elective
+export const CREATE_ELECTIVE_DOC = gql`
+  mutation CreateElective($input: CreateElectiveInput!) {
+    createElective(input: $input) {
+      id
+    }
+  }
+`;
+
+// ── 更新选修课 mutation（@contract-pending）────────────────────
+// schema 无 Mutation 类型 → MSW 兜底
+// 用于 /shell/teacher/elective/[id]/edit 编辑表单页保存
+// 契约工单：core-edu_contract.md#update-elective
+export const UPDATE_ELECTIVE_DOC = gql`
+  mutation UpdateElective($input: UpdateElectiveInput!) {
+    updateElective(input: $input) {
+      id
+    }
+  }
+`;