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

src/modules/textbooks/actions.ts

@@ -14,7 +14,9 @@ import {
     updateKnowledgePoint,
     updateTextbook,
     deleteTextbook,
-    reorderChapters
+    reorderChapters,
+    verifyChapterBelongsToTextbook,
+    verifyKnowledgePointBelongsToTextbook,
 } from "./data-access";
 import {
     CreateTextbookSchema,
@@ -38,6 +40,11 @@ export async function reorderChaptersAction(
 ): Promise<ActionState> {
     try {
         await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验：防止越权操作其他教材的章节
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
         await reorderChapters(chapterId, newIndex, parentId);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Chapters reordered successfully" };
@@ -203,6 +210,11 @@ export async function updateChapterContentAction(
 
     try {
         await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
         await updateChapterContent(parsed.data);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Content updated successfully" };
@@ -220,6 +232,11 @@ export async function deleteChapterAction(
 ): Promise<ActionState> {
     try {
         await requirePermission(Permissions.TEXTBOOK_DELETE);
+        // P0-4 资源归属校验
+        const belongs = await verifyChapterBelongsToTextbook(chapterId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
         await deleteChapter(chapterId);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Chapter deleted successfully" };
@@ -254,6 +271,11 @@ export async function createKnowledgePointAction(
 
     try {
         await requirePermission(Permissions.TEXTBOOK_CREATE);
+        // P0-4 资源归属校验：确保 chapter 属于该 textbook，防止跨教材越权创建知识点
+        const chapterBelongs = await verifyChapterBelongsToTextbook(chapterId, textbookId);
+        if (!chapterBelongs) {
+            return { success: false, message: "Chapter does not belong to this textbook" };
+        }
         await createKnowledgePoint(parsed.data);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Knowledge point created successfully" };
@@ -271,6 +293,11 @@ export async function deleteKnowledgePointAction(
 ): Promise<ActionState> {
     try {
         await requirePermission(Permissions.TEXTBOOK_DELETE);
+        // P0-4 资源归属校验
+        const belongs = await verifyKnowledgePointBelongsToTextbook(kpId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Knowledge point does not belong to this textbook" };
+        }
         await deleteKnowledgePoint(kpId);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Knowledge point deleted successfully" };
@@ -305,6 +332,11 @@ export async function updateKnowledgePointAction(
 
     try {
         await requirePermission(Permissions.TEXTBOOK_UPDATE);
+        // P0-4 资源归属校验
+        const belongs = await verifyKnowledgePointBelongsToTextbook(kpId, textbookId)
+        if (!belongs) {
+            return { success: false, message: "Knowledge point does not belong to this textbook" };
+        }
         await updateKnowledgePoint(parsed.data);
         revalidatePath(`/teacher/textbooks/${textbookId}`);
         return { success: true, message: "Knowledge point updated successfully" };