feat(lesson-preparation): 备课模块审计重构 — 跨模块解耦 + i18n + 纯函数抽取 + 错误边界

P0-1 跨模块直查修复：publish-service 不再直查 examQuestions 表，新增 exams/data-access.addExamQuestions 接口，复用 classes/data-access.getStudentIdsByClassIds

P0-2 i18n 接入：新增 zh-CN/en 翻译文件，注册 lessonPreparation 命名空间，17 个组件改造为 useTranslations/getTranslations

P1 纯函数抽取：lib/document-migration.ts（类型守卫替代 as 断言）、lib/node-summary.ts（翻译函数注入）、lib/rf-mappers.ts

P1 错误边界+骨架屏：新增 LessonPlanErrorBoundary 和 4 个 Skeleton 组件

P1 Block 注册表：新增 config/block-registry.tsx（BlockRenderer 组件），node-edit-panel 重构为配置驱动渲染

P1 其他修复：exercise-block 改用 router.refresh()，node-editor/lesson-node 复用 lib/ 纯函数

架构图同步：更新 004 和 005 文档

Refs: docs/architecture/audit/lesson-preparation-audit-report.md

src/shared/i18n/messages/en/lesson-preparation.json

@@ -0,0 +1,198 @@
+{
+  "title": {
+    "list": "My Lesson Plans",
+    "new": "New Lesson Plan",
+    "edit": "Edit Lesson Plan"
+  },
+  "description": {
+    "list": "Manage your lesson preparation and teaching plans."
+  },
+  "action": {
+    "new": "New Lesson Plan",
+    "back": "Back to Lesson Plans",
+    "addNode": "Add Node",
+    "saveVersion": "Save Version",
+    "versions": "Versions",
+    "duplicate": "Duplicate",
+    "archive": "Archive",
+    "delete": "Delete Node",
+    "close": "Close",
+    "cancel": "Cancel",
+    "confirm": "Confirm",
+    "create": "Create Lesson Plan",
+    "publish": "Publish as Homework",
+    "viewHomework": "View"
+  },
+  "status": {
+    "saving": "Saving...",
+    "unsaved": "Unsaved",
+    "saved": "Saved",
+    "draft": "Draft",
+    "published": "Published",
+    "archived": "Archived",
+    "publishedAsHomework": "Published as Homework"
+  },
+  "blockType": {
+    "objective": "Objective",
+    "key_point": "Key Points",
+    "import": "Introduction",
+    "new_teaching": "New Teaching",
+    "consolidation": "Consolidation",
+    "summary": "Summary",
+    "homework": "Homework",
+    "blackboard": "Blackboard Design",
+    "text_study": "Text Study",
+    "exercise": "Exercise",
+    "rich_text": "Custom Section",
+    "reflection": "Reflection"
+  },
+  "template": {
+    "regular": "Regular Lesson",
+    "review": "Review Lesson",
+    "experiment": "Experiment Lesson",
+    "inquiry": "Inquiry Lesson",
+    "blank": "Blank Template",
+    "selectLabel": "Select Template",
+    "titleLabel": "Lesson Plan Title",
+    "titlePlaceholder": "e.g., Autumn - Lesson 1",
+    "blockCount": "{count} sections",
+    "blankHint": "Start from scratch"
+  },
+  "editor": {
+    "canvasEmpty": "Canvas is empty",
+    "canvasEmptyHint": "Click \"Add Node\" at the bottom left to start",
+    "selectNodeHint": "Click a node to edit content, or drag to connect",
+    "unknownBlockType": "Unknown node type",
+    "nodeSummaryEmpty": "Empty",
+    "questionCount": "{count} questions",
+    "charCount": "{count} chars"
+  },
+  "filters": {
+    "searchPlaceholder": "Search title...",
+    "allSubjects": "All Subjects",
+    "allStatus": "All Status"
+  },
+  "list": {
+    "empty": "No lesson plans. Click \"New Lesson Plan\" to start",
+    "noTextbook": "No textbook",
+    "noChapter": "No chapter",
+    "noTemplate": "No template",
+    "lastSaved": "Last saved: ",
+    "neverSaved": "Never saved"
+  },
+  "version": {
+    "title": "Version History",
+    "empty": "No versions",
+    "loading": "Loading...",
+    "auto": "Auto",
+    "manual": "Manual save",
+    "revert": "Revert to this version",
+    "revertConfirm": "Revert to v{versionNo}? A new version will be created.",
+    "autoLabel": "Auto version"
+  },
+  "knowledgePoint": {
+    "title": "Select Knowledge Points",
+    "empty": "No knowledge points found. Please create them in the textbook module first.",
+    "linked": "Linked to {count} knowledge points",
+    "annotate": "Annotate Knowledge Points",
+    "select": "Select Knowledge Points",
+    "selected": "{count} selected"
+  },
+  "questionBank": {
+    "title": "Select Questions from Bank",
+    "add": "Add",
+    "insert": "Insert",
+    "selected": "{count} questions selected",
+    "source": {
+      "bank": "Bank",
+      "inline": "New"
+    },
+    "inlineTitle": "New Question (in lesson plan)",
+    "inlineNew": "New Question",
+    "fromBank": "Add from Bank",
+    "score": "{score} pts",
+    "difficulty": "{level} star",
+    "empty": "No questions. Click the button below to add",
+    "inlineQuestion": "New question in lesson plan",
+    "questionId": "Question {id}",
+    "type": {
+      "single_choice": "Single Choice",
+      "text": "Fill in Blank",
+      "judgment": "True/False"
+    },
+    "typeLabel": "Question Type",
+    "stemLabel": "Question Stem",
+    "optionsLabel": "Options (check correct answer)",
+    "addOption": "+ Add Option",
+    "correctAnswer": "Correct Answer",
+    "correct": "True",
+    "incorrect": "False",
+    "difficultyLabel": "Difficulty",
+    "knowledgePointLabel": "Knowledge Points",
+    "stemRequired": "Please enter the question stem",
+    "addBtn": "Add"
+  },
+  "exercise": {
+    "purpose": {
+      "class_practice": "Class Practice",
+      "after_class_homework": "After-class Homework"
+    }
+  },
+  "publish": {
+    "title": "Publish as Homework",
+    "classLabel": "Target Classes",
+    "availableAtLabel": "Available At (optional)",
+    "dueAtLabel": "Due At (optional)",
+    "publishing": "Publishing...",
+    "publish": "Publish",
+    "selectClass": "Please select at least one class",
+    "noStudents": "No students in selected classes",
+    "noSubjectOrGrade": "Lesson plan missing subject or grade info",
+    "alreadyPublished": "This exercise block is already published. Use 'Republish'",
+    "noExerciseBlock": "Exercise block not found",
+    "noQuestions": "No questions in exercise block",
+    "planNotFound": "Lesson plan not found",
+    "noPermission": "No permission to publish"
+  },
+  "textStudy": {
+    "sourceTextLabel": "Source Text",
+    "sourceTextPlaceholder": "Paste source text, select text to add annotations",
+    "addAnnotation": "Add Annotation for Selection",
+    "selectFirst": "Please select text first",
+    "annotationTitle": "Teaching Node",
+    "annotationNotePlaceholder": "Teaching notes..."
+  },
+  "reflection": {
+    "hint": "Write teaching reflection after class..."
+  },
+  "richText": {
+    "placeholder": "Enter content..."
+  },
+  "error": {
+    "getList": "Failed to get lesson plan list",
+    "getOne": "Failed to get lesson plan",
+    "create": "Failed to create lesson plan",
+    "save": "Failed to save",
+    "saveVersion": "Failed to save version",
+    "getVersions": "Failed to get versions",
+    "revert": "Failed to revert",
+    "delete": "Failed to delete",
+    "duplicate": "Failed to duplicate",
+    "getTemplates": "Failed to get templates",
+    "saveTemplate": "Failed to save template",
+    "deleteTemplate": "Failed to delete template",
+    "publish": "Failed to publish",
+    "aiSuggest": "AI suggestion failed. Please check AI Provider config",
+    "loadKnowledgePoints": "Failed to load knowledge points",
+    "notFound": "Lesson plan not found or no access",
+    "versionNotFound": "Version not found or no permission",
+    "templateNotFound": "Template not found",
+    "createFailed": "Creation failed",
+    "loadFailed": "Page load failed",
+    "loadFailedDesc": "Sorry, an unexpected error occurred. Please try again later.",
+    "retry": "Retry"
+  },
+  "confirm": {
+    "archive": "Archive this lesson plan?"
+  }
+}