feat(textbooks): 教材模块审计重构 — 跨模块解耦 + 权限 + i18n + 错误边界 + 纯函数抽取

P0 修复：
- 解耦跨模块 UI 依赖：knowledge-point-dialogs 不再直接 import questions，
  改为 renderQuestionCreator render prop 由页面注入
- 接入 usePermission Hook 替换 canEdit 硬编码
- 全模块 i18n 改造：新增 en/zh-CN 翻译文件，替换所有硬编码文案
- Server Action 资源归属校验：新增 verifyChapterBelongsToTextbook/
  verifyKnowledgePointBelongsToTextbook，在 reorder/update/delete/create 中校验

P1 改进：
- 补齐 Error Boundary：4 个 error.tsx + TextbookSectionErrorBoundary 区块包裹
- 抽取纯函数到 utils.ts/graph-layout.ts/constants.ts 并补单测（26 用例全通过）
- 消除重复组件：删除 knowledge-point-panel/create-knowledge-point-dialog
- 修复类型断言：chapter.children! → 守卫式访问
- 图谱 a11y：添加 role/aria-label/aria-pressed
- 统一删除确认：confirm() → AlertDialog
- 数据范围过滤：getTextbooksWithScope 支持学生端按年级过滤

P2 预留：
- TextbookAnalytics 埋点接口 + Provider + Hook

同步 005 架构数据 JSON：补充 getTextbooksWithScope/verify*/ChapterTreeNode 等

docs/architecture/005_architecture_data.json

@@ -4220,6 +4220,34 @@
             "usedBy": [
               "questions/data-access.getKnowledgePointOptions"
             ]
+          },
+          {
+            "name": "getTextbooksWithScope",
+            "signature": "(query?, subject?, grade?, scope?: TextbookQueryScope) => Promise<Textbook[]>",
+            "purpose": "P1-1 新增：按数据范围获取教材列表，学生端强制按年级过滤",
+            "usedBy": [
+              "student/learning/textbooks/page.tsx"
+            ]
+          },
+          {
+            "name": "verifyChapterBelongsToTextbook",
+            "signature": "(chapterId, textbookId) => Promise<boolean>",
+            "purpose": "P0-4 新增：资源归属校验，防止跨教材越权操作章节",
+            "usedBy": [
+              "reorderChaptersAction",
+              "updateChapterContentAction",
+              "deleteChapterAction",
+              "createKnowledgePointAction"
+            ]
+          },
+          {
+            "name": "verifyKnowledgePointBelongsToTextbook",
+            "signature": "(kpId, textbookId) => Promise<boolean>",
+            "purpose": "P0-4 新增：资源归属校验，防止跨教材越权操作知识点",
+            "usedBy": [
+              "updateKnowledgePointAction",
+              "deleteKnowledgePointAction"
+            ]
           }
         ],
         "hooks": [
@@ -4251,6 +4279,15 @@
               "questions (知识点关联)"
             ]
           },
+          {
+            "name": "ChapterTreeNode",
+            "definition": "Chapter & { children: ChapterTreeNode[] }",
+            "purpose": "P1-5 新增：buildChapterTree 返回类型，强制 children 为非空数组",
+            "usedBy": [
+              "textbooks/utils.buildChapterTree",
+              "textbooks/components/chapter-sidebar-list.tsx"
+            ]
+          },
           {
             "name": "KnowledgePoint",
             "definition": "{ id, name, description?, anchorText?, parentId?, chapterId?, level, order }",