feat(textbooks): 知识图谱功能全面重构 — 前置依赖 + dagre 布局 + React Flow 可视化 + 师生双视角

将教材模块图谱从基本无用状态升级为完整知识图谱可视化系统。

数据层：新增 knowledgePointPrerequisites 表（复合主键+双外键 cascade）；新增 data-access-graph.ts（server-only）知识点关联聚合、学生/班级掌握度查询；utils.ts 新增 hasCycleAfterAddingEdge（DFS 循环依赖检测）。

业务层：3 个新 Server Action（getKnowledgeGraphDataAction 三视图模式、createPrerequisiteAction 含循环检测、deletePrerequisiteAction）；graph-layout.ts 重写为 dagre 分层有向图布局。

视图层：knowledge-graph.tsx 重写为 React Flow 主组件（全书视图+搜索高亮+关联节点高亮+章节着色）；4 个新组件（graph-kp-node/graph-prerequisite-edge/graph-toolbar/graph-node-detail-panel）；use-graph-data.ts 派生值模式避免 effect 中 setState。

架构：严格三层架构，客户端通过 Server Action 间接访问 server-only 数据层；权限校验+ i18n 全覆盖；架构文档 004/005 同步。

测试：utils.test.ts 新增 5 个循环检测测试，graph-layout.test.ts 重写 5 个 dagre 布局测试，全部 30 个教材模块单元测试通过。

附带提交 drizzle/0005 error-book 迁移文件以保持 journal 一致性。

src/modules/textbooks/data-access.ts

@@ -5,7 +5,8 @@ import { and, asc, count, eq, inArray, like, or, sql, isNull, type SQL } from "d
 import { createId } from "@paralleldrive/cuid2"
 
 import { db } from "@/shared/db"
-import { chapters, knowledgePoints, textbooks } from "@/shared/db/schema"
+import { chapters, knowledgePoints, knowledgePointPrerequisites, textbooks } from "@/shared/db/schema"
+import { escapeLikePattern } from "@/shared/lib/action-utils"
 import type {
   Chapter,
   KnowledgePoint,
@@ -14,7 +15,9 @@ import type {
 import type {
   CreateChapterInput,
   CreateKnowledgePointInput,
+  CreatePrerequisiteInput,
   CreateTextbookInput,
+  DeletePrerequisiteInput,
   UpdateChapterContentInput,
   UpdateKnowledgePointInput,
   UpdateTextbookInput,
@@ -41,7 +44,7 @@ export const getTextbooks = cache(async (query?: string, subject?: string, grade
 
   const q = query?.trim()
   if (q) {
-    const needle = `%${q}%`
+    const needle = `%${escapeLikePattern(q)}%`
     const nameCond = or(
       like(textbooks.title, needle),
       like(textbooks.subject, needle),
@@ -288,8 +291,10 @@ export async function deleteChapter(id: string): Promise<void> {
     if (kids) stack.push(...kids)
   }
 
-  await db.delete(knowledgePoints).where(inArray(knowledgePoints.chapterId, idsToDelete))
-  await db.delete(chapters).where(inArray(chapters.id, idsToDelete))
+  await db.transaction(async (tx) => {
+    await tx.delete(knowledgePoints).where(inArray(knowledgePoints.chapterId, idsToDelete))
+    await tx.delete(chapters).where(inArray(chapters.id, idsToDelete))
+  })
 }
 
 export const getKnowledgePointsByChapterId = cache(async (chapterId: string): Promise<KnowledgePoint[]> => {
@@ -505,7 +510,7 @@ export const getTextbooksWithScope = cache(
 
     const q = query?.trim()
     if (q) {
-      const needle = `%${q}%`
+      const needle = `%${escapeLikePattern(q)}%`
       const nameCond = or(
         like(textbooks.title, needle),
         like(textbooks.subject, needle),
@@ -617,3 +622,41 @@ export const getKnowledgePointOptions = cache(async (): Promise<KnowledgePointOp
     grade: row.grade ?? null,
   }))
 })
+
+// ===== Prerequisite CRUD =====
+
+export async function createPrerequisite(data: CreatePrerequisiteInput): Promise<void> {
+  await db.insert(knowledgePointPrerequisites).values({
+    knowledgePointId: data.knowledgePointId,
+    prerequisiteKpId: data.prerequisiteKpId,
+  })
+}
+
+export async function deletePrerequisite(data: DeletePrerequisiteInput): Promise<void> {
+  await db
+    .delete(knowledgePointPrerequisites)
+    .where(and(
+      eq(knowledgePointPrerequisites.knowledgePointId, data.knowledgePointId),
+      eq(knowledgePointPrerequisites.prerequisiteKpId, data.prerequisiteKpId),
+    ))
+}
+
+/**
+ * 获取教材下所有知识点的前置依赖边列表。
+ * 用于循环检测。
+ */
+export async function getPrerequisiteEdgesForTextbook(
+  textbookId: string,
+): Promise<Array<[string, string]>> {
+  const rows = await db
+    .select({
+      knowledgePointId: knowledgePointPrerequisites.knowledgePointId,
+      prerequisiteKpId: knowledgePointPrerequisites.prerequisiteKpId,
+    })
+    .from(knowledgePointPrerequisites)
+    .innerJoin(knowledgePoints, eq(knowledgePoints.id, knowledgePointPrerequisites.knowledgePointId))
+    .innerJoin(chapters, eq(chapters.id, knowledgePoints.chapterId))
+    .where(eq(chapters.textbookId, textbookId))
+
+  return rows.map((r) => [r.knowledgePointId, r.prerequisiteKpId] as [string, string])
+}