fix(textbooks): 规范核查修复 — 安全漏洞+功能缺失+i18n+类型安全

安全：createPrerequisiteAction 补充 prerequisiteKpId 归属校验；deletePrerequisiteAction 补充双知识点归属校验，防止跨教材越权。

功能：实现图谱添加/删除前置依赖（Dialog + Select 选择知识点 + 调用 Server Action + 自动刷新图谱），替换原 no-op 回调。

i18n：修复 8 处硬编码英文字符串（textbook-reader/chapter-sidebar-list/textbook-card/textbook-form-dialog/textbook-settings-dialog/create-chapter-dialog/teacher-textbook-reader），新增 saveFailed/createFailed/updateFailed/deleteFailed/questionCreatorDefaultContent 等 key。

类型安全：graph-prerequisite-edge.tsx 使用 GraphEdgeData 类型经 unknown 安全转换，替代裸 as 断言。

规范：analytics.tsx 移动 use client 指令到文件第一行；同步架构文档 005 JSON 类型定义（GraphNodeData/GraphEdgeData/MasteryLevel）。

验证：教材模块 lint 零错误、tsc 零错误、193 个单元测试全部通过。

docs/architecture/005_architecture_data.json

@@ -4508,8 +4508,8 @@
           {
             "name": "GraphNodeData",
             "type": "interface",
-            "definition": "{ id, name, chapterId, chapterTitle, level, questionCount, mastery?: MasteryInfo, isHighlighted?, isRelated?, searchText? } & Record<string, unknown>",
-            "purpose": "Task 9 新增：React Flow 自定义节点数据（含索引签名满足 React Flow 约束）",
+            "definition": "{ kp: KpWithRelations, mastery: MasteryInfo | null, viewMode: GraphViewMode, isSelected: boolean, isHighlighted: boolean, chapterColor: string }",
+            "purpose": "Task 9 新增：React Flow 自定义节点数据（传递给 graph-kp-node 组件）",
             "usedBy": [
               "components/graph-kp-node.tsx",
               "components/knowledge-graph.tsx"
@@ -4518,7 +4518,7 @@
           {
             "name": "GraphEdgeData",
             "type": "interface",
-            "definition": "{ edgeType: 'parent-child' | 'prerequisite', isHighlighted? } & Record<string, unknown>",
+            "definition": "{ edgeType: 'parent' | 'prerequisite', isHighlighted: boolean }",
             "purpose": "Task 9 新增：React Flow 自定义边数据",
             "usedBy": [
               "components/graph-prerequisite-edge.tsx",
@@ -4528,8 +4528,8 @@
           {
             "name": "MasteryLevel",
             "type": "type",
-            "definition": "'unknown' | 'weak' | 'fair' | 'strong'",
-            "purpose": "Task 9 新增：掌握度等级（红/黄/灰）",
+            "definition": "'low' | 'medium' | 'high' | 'unassessed'",
+            "purpose": "Task 9 新增：掌握度等级（红/黄/绿/灰）",
             "usedBy": [
               "components/graph-kp-node.tsx"
             ]
@@ -13694,8 +13694,12 @@
       "algorithms": {
         "sm2": {
           "name": "SM-2 间隔重复算法（简化版）",
-          "description": "4 级评级（again/hard/good/easy），间隔 1/2/4/7 天起，指数增长（×1.2/×1.5/×2），连续 3 次答对标记为已掌握",
-          "functions": ["calculateNewInterval", "calculateNewMastery", "deriveStatus", "calculateNextReviewAt"]
+          "file": "sm2-algorithm.ts",
+          "description": "独立纯函数模块，4 级评级（again/hard/good/easy），间隔 1/2/4/7 天起，指数增长（×1.2/×1.5/×2），连续 3 次答对标记为已掌握。支持时间注入便于测试。",
+          "functions": ["calculateNewInterval", "calculateNewMastery", "deriveStatus", "calculateNextReviewAt", "calculateNewCorrectStreak", "calculateSm2Result"],
+          "constants": ["REVIEW_INTERVALS", "INTERVAL_MULTIPLIERS", "MAX_MASTERY_LEVEL", "MIN_MASTERY_LEVEL", "MASTERED_REQUIRED_STREAK", "MASTERED_REQUIRED_MASTERY"],
+          "testFile": "sm2-algorithm.test.ts",
+          "testCount": 39
         }
       },
       "dataScope": {