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-card.tsx

@@ -1,12 +1,17 @@
 "use client";
 
 import Link from "next/link";
+import { useRouter } from "next/navigation";
+import { useTranslations } from "next-intl";
 import { Button } from "@/shared/components/ui/button";
-import { LESSON_PLAN_STATUS_LABELS } from "../constants";
+import { formatDateTime } from "@/shared/lib/utils";
 import { duplicateLessonPlanAction, deleteLessonPlanAction } from "../actions";
 import type { LessonPlanListItem } from "../types";
 
 export function LessonPlanCard({ plan }: { plan: LessonPlanListItem }) {
+  const t = useTranslations("lessonPreparation");
+  const router = useRouter();
+
   return (
     <div className="border border-outline-variant rounded-lg p-4 bg-surface-container-lowest hover:shadow-md transition-shadow">
       <Link
@@ -18,17 +23,17 @@ export function LessonPlanCard({ plan }: { plan: LessonPlanListItem }) {
         </h3>
       </Link>
       <div className="text-sm text-on-surface-variant mt-1">
-        {plan.textbookTitle ?? "无教材"} · {plan.chapterTitle ?? "无章节"}
+        {plan.textbookTitle ?? t("list.noTextbook")} · {plan.chapterTitle ?? t("list.noChapter")}
       </div>
       <div className="text-xs text-on-surface-variant mt-1">
-        {plan.templateName ?? "无模板"} ·{" "}
-        {LESSON_PLAN_STATUS_LABELS[plan.status]}
+        {plan.templateName ?? t("list.noTemplate")} ·{" "}
+        {t(`status.${plan.status}`)}
       </div>
       <div className="text-xs text-on-surface-variant mt-2">
-        最后保存：
+        {t("list.lastSaved")}
         {plan.lastSavedAt
-          ? new Date(plan.lastSavedAt).toLocaleString()
-          : "未保存"}
+          ? formatDateTime(plan.lastSavedAt)
+          : t("list.neverSaved")}
       </div>
       <div className="flex gap-2 mt-3">
         <Button
@@ -36,21 +41,21 @@ export function LessonPlanCard({ plan }: { plan: LessonPlanListItem }) {
           size="sm"
           onClick={async () => {
             const res = await duplicateLessonPlanAction(plan.id);
-            if (res.success) window.location.reload();
+            if (res.success) router.refresh();
           }}
         >
-          复制
+          {t("action.duplicate")}
         </Button>
         <Button
           variant="outline"
           size="sm"
           onClick={async () => {
-            if (!confirm("确认归档此课案？")) return;
+            if (!confirm(t("confirm.archive"))) return;
             const res = await deleteLessonPlanAction(plan.id);
-            if (res.success) window.location.reload();
+            if (res.success) router.refresh();
           }}
         >
-          归档
+          {t("action.archive")}
         </Button>
       </div>
     </div>