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/modules/lesson-preparation/components/lesson-plan-editor.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { useCallback, useEffect, useRef, useState } from "react";
+import { useTranslations } from "next-intl";
 import { useLessonPlanEditor } from "../hooks/use-lesson-plan-editor";
 import { NodeEditor } from "./node-editor";
 import { NodeEditPanel } from "./node-edit-panel";
@@ -10,7 +11,6 @@ import {
   saveLessonPlanVersionAction,
   getLessonPlanByIdAction,
 } from "../actions";
-import { BLOCK_TYPE_LABELS } from "../constants";
 import type { BlockType } from "../types";
 import { Button } from "@/shared/components/ui/button";
 import { Plus, Save, History } from "lucide-react";
@@ -47,10 +47,10 @@ export function LessonPlanEditor({
   chapterId,
   classes,
 }: Props) {
+  const t = useTranslations("lessonPreparation");
   const editor = useLessonPlanEditor();
   const [showVersions, setShowVersions] = useState(false);
   const [showAddMenu, setShowAddMenu] = useState(false);
-  const [panelOpen, setPanelOpen] = useState(false);
   const autoSaveTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
   const versionTimer = useRef<ReturnType<typeof setInterval> | null>(null);
   const addMenuRef = useRef<HTMLDivElement>(null);
@@ -62,11 +62,6 @@ export function LessonPlanEditor({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [initKey]);
 
-  // 选中节点时打开侧边面板
-  useEffect(() => {
-    if (editor.selectedNodeId) setPanelOpen(true);
-  }, [editor.selectedNodeId]);
-
   // 自动保存（debounce 3s）- 用 getState() 获取最新值（修复 P1-4）
   useEffect(() => {
     if (!editor.isDirty) return;
@@ -95,13 +90,13 @@ export function LessonPlanEditor({
       await saveLessonPlanVersionAction({
         planId: state.planId,
         content: state.doc,
-        label: "自动版本",
+        label: t("version.autoLabel"),
       });
     }, 30 * 60 * 1000);
     return () => {
       if (versionTimer.current) clearInterval(versionTimer.current);
     };
-  }, [planId]);
+  }, [planId, t]);
 
   // 离开未保存提示（P3-1）
   useEffect(() => {
@@ -158,20 +153,20 @@ export function LessonPlanEditor({
         />
         <span className="text-on-surface-variant text-sm">
           {editor.isSaving
-            ? "保存中..."
+            ? t("status.saving")
             : editor.isDirty
-              ? "未保存"
-              : "已保存"}
+              ? t("status.unsaved")
+              : t("status.saved")}
         </span>
         <Button
           variant="outline"
           size="sm"
           onClick={() => setShowVersions(true)}
         >
-          <History className="w-4 h-4 mr-1" /> 版本
+          <History className="w-4 h-4 mr-1" /> {t("action.versions")}
         </Button>
         <Button size="sm" onClick={handleManualSave} disabled={editor.isSaving}>
-          <Save className="w-4 h-4 mr-1" /> 保存版本
+          <Save className="w-4 h-4 mr-1" /> {t("action.saveVersion")}
         </Button>
       </div>
 
@@ -179,31 +174,27 @@ export function LessonPlanEditor({
       <div className="flex-1 flex overflow-hidden">
         {/* 节点画布 */}
         <div className="flex-1 relative">
-          <NodeEditor
-            textbookId={textbookId}
-            chapterId={chapterId}
-            classes={classes}
-          />
+          <NodeEditor />
           {/* 添加节点浮动按钮 */}
           <div className="absolute bottom-4 left-4 z-10" ref={addMenuRef}>
             <Button
               variant="default"
               onClick={() => setShowAddMenu(!showAddMenu)}
             >
-              <Plus className="w-4 h-4 mr-1" /> 添加节点
+              <Plus className="w-4 h-4 mr-1" /> {t("action.addNode")}
             </Button>
             {showAddMenu && (
               <div className="absolute bottom-12 left-0 bg-surface border border-outline-variant rounded-lg shadow-lg p-2 grid grid-cols-2 gap-1 w-72 max-h-[60vh] overflow-y-auto">
-                {BLOCK_TYPES_TO_ADD.map((t) => (
+                {BLOCK_TYPES_TO_ADD.map((blockType) => (
                   <button
-                    key={t}
+                    key={blockType}
                     onClick={() => {
-                      editor.addNode(t);
+                      editor.addNode(blockType);
                       setShowAddMenu(false);
                     }}
                     className="text-left px-2 py-1 text-sm hover:bg-surface-container-highest rounded"
                   >
-                    {BLOCK_TYPE_LABELS[t]}
+                    {t(`blockType.${blockType}`)}
                   </button>
                 ))}
               </div>
@@ -211,8 +202,8 @@ export function LessonPlanEditor({
           </div>
         </div>
 
-        {/* 侧边内容编辑面板 */}
-        {panelOpen && editor.selectedNodeId && (
+        {/* 侧边内容编辑面板：直接用 selectedNodeId 控制显示（修复 P1-2） */}
+        {editor.selectedNodeId && (
           <div className="w-[420px] flex-shrink-0">
             <NodeEditPanel
               textbookId={textbookId}