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/shared/db/schema.ts

@@ -153,6 +153,27 @@ export const knowledgePoints = mysqlTable("knowledge_points", {
   chapterIdIdx: index("kp_chapter_id_idx").on(table.chapterId),
 }));
 
+// --- 知识点前置依赖（知识图谱） ---
+export const knowledgePointPrerequisites = mysqlTable("knowledge_point_prerequisites", {
+  knowledgePointId: varchar("knowledge_point_id", { length: 128 }).notNull(),
+  prerequisiteKpId: varchar("prerequisite_kp_id", { length: 128 }).notNull(),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+}, (table) => ({
+  kpPairPk: primaryKey({ columns: [table.knowledgePointId, table.prerequisiteKpId] }),
+  kpIdx: index("kp_prereq_kp_idx").on(table.knowledgePointId),
+  prereqIdx: index("kp_prereq_prereq_idx").on(table.prerequisiteKpId),
+  kpFk: foreignKey({
+    columns: [table.knowledgePointId],
+    foreignColumns: [knowledgePoints.id],
+    name: "kp_prereq_kp_fk",
+  }).onDelete("cascade"),
+  prereqFk: foreignKey({
+    columns: [table.prerequisiteKpId],
+    foreignColumns: [knowledgePoints.id],
+    name: "kp_prereq_prereq_fk",
+  }).onDelete("cascade"),
+}));
+
 // --- 3. Question Bank (Core) ---
 
 export const questionTypeEnum = mysqlEnum("type", ["single_choice", "multiple_choice", "text", "judgment", "composite"]);
@@ -1337,3 +1358,85 @@ export const systemSettings = mysqlTable("system_settings", {
   categoryKeyIdx: uniqueIndex("ss_category_key_idx").on(table.category, table.key),
   categoryIdx: index("ss_category_idx").on(table.category),
 }));
+
+// --- 26. Error Book (错题本) ---
+
+export const errorBookSourceTypeEnum = mysqlEnum("source_type", ["exam", "homework", "manual"]);
+export const errorBookStatusEnum = mysqlEnum("error_status", ["new", "learning", "mastered", "archived"]);
+export const errorBookReviewResultEnum = mysqlEnum("review_result", ["again", "hard", "good", "easy"]);
+
+/**
+ * 错题本条目 - 存储学生的错题记录。
+ * 来源可以是考试提交、作业提交，或学生手动添加。
+ * 采用简化版 SM-2 间隔重复算法调度复习。
+ */
+export const errorBookItems = mysqlTable("error_book_items", {
+  id: id("id").primaryKey(),
+  studentId: varchar("student_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  questionId: varchar("question_id", { length: 128 }).notNull().references(() => questions.id),
+
+  // 来源
+  sourceType: errorBookSourceTypeEnum.default("manual").notNull(),
+  /** exam_submission_id / homework_submission_id / null（手动添加） */
+  sourceId: varchar("source_id", { length: 128 }),
+
+  // 作答快照（冗余存储，避免源记录被删除后丢失上下文）
+  studentAnswer: json("student_answer"),
+  correctAnswer: json("correct_answer"),
+
+  // 分类元数据（冗余，加速筛选）
+  subjectId: varchar("subject_id", { length: 128 }),
+  knowledgePointIds: json("knowledge_point_ids"),
+
+  // 状态与掌握度
+  status: errorBookStatusEnum.default("new").notNull(),
+  /** 0-5 掌握程度，0=未学，5=已掌握 */
+  masteryLevel: int("mastery_level").default(0).notNull(),
+
+  // SM-2 间隔重复参数
+  nextReviewAt: timestamp("next_review_at", { mode: "date" }),
+  /** 复习间隔（天） */
+  reviewInterval: int("review_interval").default(1).notNull(),
+  reviewCount: int("review_count").default(0).notNull(),
+  /** 连续答对次数（用于判断是否标记为已掌握） */
+  correctStreak: int("correct_streak").default(0).notNull(),
+
+  // 学生笔记与反思
+  note: text("note"),
+  /** 错误原因标签（JSON 数组，如 ["粗心", "概念不清", "计算错误"]） */
+  errorTags: json("error_tags"),
+
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().onUpdateNow().notNull(),
+}, (table) => ({
+  studentIdx: index("eb_item_student_idx").on(table.studentId),
+  studentStatusIdx: index("eb_item_student_status_idx").on(table.studentId, table.status),
+  studentReviewIdx: index("eb_item_student_review_idx").on(table.studentId, table.nextReviewAt),
+  questionIdx: index("eb_item_question_idx").on(table.questionId),
+  subjectIdx: index("eb_item_subject_idx").on(table.subjectId),
+  sourceIdx: index("eb_item_source_idx").on(table.sourceType, table.sourceId),
+}));
+
+/**
+ * 错题复习记录 - 每次复习的历史快照。
+ * 用于追踪复习进度和算法调参。
+ */
+export const errorBookReviews = mysqlTable("error_book_reviews", {
+  id: id("id").primaryKey(),
+  itemId: varchar("item_id", { length: 128 }).notNull().references(() => errorBookItems.id, { onDelete: "cascade" }),
+  studentId: varchar("student_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+
+  /** 复习自评结果：again(重来) / hard(困难) / good(良好) / easy(简单) */
+  result: errorBookReviewResultEnum.notNull(),
+  reviewedAt: timestamp("reviewed_at").defaultNow().notNull(),
+
+  /** 本次复习后的新间隔（天） */
+  newInterval: int("new_interval"),
+  newMasteryLevel: int("new_mastery_level"),
+
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+}, (table) => ({
+  itemIdx: index("eb_review_item_idx").on(table.itemId),
+  studentIdx: index("eb_review_student_idx").on(table.studentId),
+  studentReviewedIdx: index("eb_review_student_reviewed_idx").on(table.studentId, table.reviewedAt),
+}));

src/shared/i18n/messages/en/textbooks.json

@@ -34,10 +34,16 @@
       "graph": "Graph"
     },
     "selectChapter": "Please select a chapter to start reading.",
+    "selectChapterDesc": "Choose a chapter from the sidebar to view its content.",
     "selectChapterKnowledge": "Please select a chapter to view knowledge points.",
+    "selectChapterKnowledgeDesc": "Choose a chapter from the sidebar to see its knowledge points.",
     "selectChapterGraph": "Please select a chapter to view the knowledge graph.",
+    "selectChapterGraphDesc": "Choose a chapter from the sidebar to see its knowledge graph.",
     "emptyKnowledge": "No knowledge points in this chapter yet.",
+    "emptyKnowledgeDesc": "Select text while reading to create a knowledge point.",
     "emptyContent": "No content yet",
+    "emptyContentDesc": "Click \"Edit Content\" to start writing this chapter.",
+    "loadingKnowledge": "Loading knowledge points...",
     "editContent": "Edit Content",
     "cancel": "Cancel",
     "save": "Save",
@@ -45,7 +51,9 @@
     "addKnowledgePoint": "Add Knowledge Point",
     "clickToViewKp": "Click to view knowledge point details",
     "noChapters": "No chapters",
-    "noChaptersDesc": "This textbook has no chapters yet."
+    "noChaptersDesc": "This textbook has no chapters yet.",
+    "sidebar": "Chapters & Knowledge",
+    "openSidebar": "Open Sidebar"
   },
   "dialog": {
     "create": {
@@ -75,7 +83,11 @@
       "deleting": "Deleting...",
       "cannotDeleteWithSubchapters": "Cannot delete chapter with subchapters",
       "addSubchapter": "Add Subchapter",
-      "titlePlaceholder": "e.g. Chapter 1: Introduction"
+      "titlePlaceholder": "e.g. Chapter 1: Introduction",
+      "toggle": "Toggle",
+      "orderUpdated": "Order updated",
+      "cancel": "Cancel",
+      "dragHandle": "Drag to reorder"
     },
     "knowledge": {
       "createTitle": "Add Knowledge Point",
@@ -133,6 +145,7 @@
     "level": "Lv."
   },
   "subject": {
+    "chinese": "Chinese",
     "mathematics": "Mathematics",
     "physics": "Physics",
     "chemistry": "Chemistry",
@@ -142,6 +155,8 @@
     "geography": "Geography"
   },
   "grade": {
+    "grade1": "Grade 1",
+    "grade2": "Grade 2",
     "grade7": "Grade 7",
     "grade8": "Grade 8",
     "grade9": "Grade 9",
@@ -160,7 +175,7 @@
     "updateSuccess": "Textbook updated successfully.",
     "updateFailed": "Failed to update textbook.",
     "deleteSuccess": "Textbook deleted successfully.",
-    "deleteFailed": "Failed to delete textbook.",
+    "textbookDeleteFailed": "Failed to delete textbook.",
     "chapterCreateSuccess": "Chapter created successfully",
     "chapterCreateFailed": "Failed to create chapter",
     "chapterDeleteSuccess": "Chapter deleted successfully",
@@ -181,6 +196,57 @@
     "invalidContent": "Invalid chapter content data",
     "errorOccurred": "An error occurred",
     "deleteFailed": "Deletion failed",
-    "updateFailedGeneric": "Update failed"
+    "updateFailedGeneric": "Update failed",
+    "chapterNotBelong": "Chapter does not belong to this textbook",
+    "kpNotBelong": "Knowledge point does not belong to this textbook",
+    "chaptersReordered": "Chapters reordered successfully",
+    "ok": "OK",
+    "kpLoadFailed": "Failed to load knowledge points",
+    "graphLoadFailed": "Graph failed to load",
+    "invalidInput": "Invalid input",
+    "cyclicDependency": "Cannot add cyclic dependency",
+    "prerequisiteCreated": "Prerequisite added",
+    "prerequisiteCreateFailed": "Failed to add prerequisite",
+    "prerequisiteDeleted": "Prerequisite removed",
+    "prerequisiteDeleteFailed": "Failed to remove prerequisite"
+  },
+  "graph": {
+    "viewMode": {
+      "structure": "Structure",
+      "studentMastery": "My Mastery",
+      "classMastery": "Class Mastery"
+    },
+    "node": {
+      "questions": "Questions",
+      "mastery": "Mastery",
+      "prerequisite": "Prerequisite",
+      "successor": "Successor"
+    },
+    "detail": {
+      "title": "Knowledge Point Details",
+      "noDescription": "No description",
+      "viewAllQuestions": "View all questions",
+      "editPrerequisite": "Edit prerequisites",
+      "addPrerequisite": "Add prerequisite",
+      "removePrerequisite": "Remove",
+      "noPrerequisites": "No prerequisite knowledge points",
+      "noSuccessors": "No successor knowledge points",
+      "masteryNotAssessed": "Not assessed",
+      "correctRate": "Correct rate",
+      "totalQuestions": "Total questions"
+    },
+    "toolbar": {
+      "search": "Search knowledge points",
+      "filterByChapter": "Filter by chapter",
+      "resetView": "Reset view"
+    },
+    "empty": {
+      "noPrerequisites": "No prerequisite relationships",
+      "noData": "No graph data"
+    },
+    "error": {
+      "cyclicDependency": "Cannot add cyclic dependency",
+      "loadFailed": "Graph failed to load"
+    }
   }
 }

src/shared/i18n/messages/zh-CN/textbooks.json

@@ -34,10 +34,16 @@
       "graph": "图谱"
     },
     "selectChapter": "请选择一个章节开始阅读。",
+    "selectChapterDesc": "从左侧目录中选择一个章节以查看内容。",
     "selectChapterKnowledge": "请选择一个章节查看知识点。",
+    "selectChapterKnowledgeDesc": "从左侧目录中选择一个章节以查看关联的知识点。",
     "selectChapterGraph": "请选择一个章节查看知识图谱。",
+    "selectChapterGraphDesc": "从左侧目录中选择一个章节以查看知识图谱关系。",
     "emptyKnowledge": "该章节暂无知识点。",
+    "emptyKnowledgeDesc": "在阅读内容时选中文本即可创建知识点。",
     "emptyContent": "暂无内容",
+    "emptyContentDesc": "点击「编辑内容」开始编写本章正文。",
+    "loadingKnowledge": "正在加载知识点...",
     "editContent": "编辑内容",
     "cancel": "取消",
     "save": "保存",
@@ -45,7 +51,9 @@
     "addKnowledgePoint": "添加知识点",
     "clickToViewKp": "点击查看知识点详情",
     "noChapters": "暂无章节",
-    "noChaptersDesc": "这本教材还没有章节。"
+    "noChaptersDesc": "这本教材还没有章节。",
+    "sidebar": "目录与知识点",
+    "openSidebar": "打开目录"
   },
   "dialog": {
     "create": {
@@ -75,7 +83,11 @@
       "deleting": "删除中...",
       "cannotDeleteWithSubchapters": "无法删除含有子章节的章节",
       "addSubchapter": "添加子章节",
-      "titlePlaceholder": "例如：第一章：入门"
+      "titlePlaceholder": "例如：第一章：入门",
+      "toggle": "展开/折叠",
+      "orderUpdated": "顺序已更新",
+      "cancel": "取消",
+      "dragHandle": "拖拽排序"
     },
     "knowledge": {
       "createTitle": "添加知识点",
@@ -133,6 +145,7 @@
     "level": "等级"
   },
   "subject": {
+    "chinese": "语文",
     "mathematics": "数学",
     "physics": "物理",
     "chemistry": "化学",
@@ -142,6 +155,8 @@
     "geography": "地理"
   },
   "grade": {
+    "grade1": "一年级",
+    "grade2": "二年级",
     "grade7": "七年级",
     "grade8": "八年级",
     "grade9": "九年级",
@@ -160,7 +175,7 @@
     "updateSuccess": "教材更新成功。",
     "updateFailed": "更新教材失败。",
     "deleteSuccess": "教材删除成功。",
-    "deleteFailed": "删除教材失败。",
+    "textbookDeleteFailed": "删除教材失败。",
     "chapterCreateSuccess": "章节创建成功",
     "chapterCreateFailed": "创建章节失败",
     "chapterDeleteSuccess": "章节删除成功",
@@ -181,6 +196,57 @@
     "invalidContent": "章节内容数据无效",
     "errorOccurred": "发生错误",
     "deleteFailed": "删除失败",
-    "updateFailedGeneric": "更新失败"
+    "updateFailedGeneric": "更新失败",
+    "chapterNotBelong": "章节不属于该教材",
+    "kpNotBelong": "知识点不属于该教材",
+    "chaptersReordered": "章节排序成功",
+    "ok": "成功",
+    "kpLoadFailed": "加载知识点失败",
+    "graphLoadFailed": "图谱加载失败",
+    "invalidInput": "输入无效",
+    "cyclicDependency": "不能添加循环依赖",
+    "prerequisiteCreated": "前置依赖已添加",
+    "prerequisiteCreateFailed": "添加前置依赖失败",
+    "prerequisiteDeleted": "前置依赖已删除",
+    "prerequisiteDeleteFailed": "删除前置依赖失败"
+  },
+  "graph": {
+    "viewMode": {
+      "structure": "结构图",
+      "studentMastery": "个人掌握度",
+      "classMastery": "班级掌握度"
+    },
+    "node": {
+      "questions": "题目",
+      "mastery": "掌握度",
+      "prerequisite": "前置",
+      "successor": "后置"
+    },
+    "detail": {
+      "title": "知识点详情",
+      "noDescription": "暂无描述",
+      "viewAllQuestions": "查看全部题目",
+      "editPrerequisite": "编辑前置依赖",
+      "addPrerequisite": "添加前置",
+      "removePrerequisite": "移除",
+      "noPrerequisites": "暂无前置知识点",
+      "noSuccessors": "暂无后置知识点",
+      "masteryNotAssessed": "未测评",
+      "correctRate": "正确率",
+      "totalQuestions": "总题数"
+    },
+    "toolbar": {
+      "search": "搜索知识点",
+      "filterByChapter": "按章节筛选",
+      "resetView": "重置视图"
+    },
+    "empty": {
+      "noPrerequisites": "暂无前置依赖关系",
+      "noData": "暂无图谱数据"
+    },
+    "error": {
+      "cyclicDependency": "不能添加循环依赖",
+      "loadFailed": "图谱加载失败"
+    }
   }
 }