feat(ai): 新增 AI 模块并集成至备课/错题集/试卷/改题四大业务场景

- 新增 src/modules/ai 独立模块，遵循三层架构（actions → services → shared/lib/ai）
- 通过 AiClientProvider + useAiClient 实现 React Context 依赖注入，业务组件零直接 import
- 6 个 Server Actions 均调用 requirePermission() 权限校验，返回 ActionState<T>
- withAiTracking 统一埋点，覆盖 chat/similar_question/grading_assist/lesson_content/question_variant/weakness_analysis
- 集成场景：作业批改 AiGradingAssist、错题集 AiErrorBookAnalysis、备课 AiLessonContentGenerator、试卷 AiQuestionVariantGenerator
- 全量 i18n（en/zh-CN ai.json），Error Boundary + Skeleton 边界处理
- 同步架构图 004/005，新增审计报告 ai-module-audit-report.md

src/app/(dashboard)/teacher/exams/[id]/build/page.tsx

@@ -7,13 +7,45 @@ import { normalizeStructure } from "@/modules/exams/utils/normalize-structure"
 import type { Question } from "@/modules/questions/types"
 import type { ExamNode } from "@/modules/exams/components/assembly/selected-question-list"
 import { createId } from "@paralleldrive/cuid2"
+import { requirePermission } from "@/shared/lib/auth-guard"
+import { Permissions } from "@/shared/types/permissions"
+import {
+  AiClientProvider,
+  type AiClientService,
+} from "@/modules/ai/context/ai-client-provider"
+import {
+  aiChatAction,
+  suggestSimilarQuestionsAction,
+  suggestGradingAction,
+  generateLessonContentAction,
+  generateQuestionVariantAction,
+  analyzeWeaknessAction,
+} from "@/modules/ai/actions"
 
 export const dynamic = "force-dynamic"
 
+/**
+ * 构建 AI 客户端服务（Server Action 引用集合）
+ *
+ * 通过 React Context 注入，客户端组件不直接 import actions，
+ * 遵循依赖注入模式，便于测试时替换为 mock。
+ */
+function createAiClientService(): AiClientService {
+  return {
+    chat: aiChatAction,
+    suggestSimilarQuestions: suggestSimilarQuestionsAction,
+    suggestGrading: suggestGradingAction,
+    generateLessonContent: generateLessonContentAction,
+    generateQuestionVariant: generateQuestionVariantAction,
+    analyzeWeakness: analyzeWeaknessAction,
+  }
+}
+
 export default async function BuildExamPage({ params }: { params: Promise<{ id: string }> }): Promise<JSX.Element> {
   const { id } = await params
 
-  const exam = await getExamById(id)
+  const ctx = await requirePermission(Permissions.EXAM_READ)
+  const exam = await getExamById(id, ctx.dataScope)
   if (!exam) return notFound()
 
   // Fetch initial questions for the bank (pagination handled by client)
@@ -69,24 +101,28 @@ export default async function BuildExamPage({ params }: { params: Promise<{ id:
     }))
   }
 
+  const aiClientService = createAiClientService()
+
   return (
-    <div className="flex h-full flex-col space-y-4 p-4">
-      <div>
-        <h1 className="text-2xl font-bold tracking-tight">Build Exam</h1>
-        <p className="text-muted-foreground">Assemble questions for your exam.</p>
+    <AiClientProvider service={aiClientService}>
+      <div className="flex h-full flex-col space-y-4 p-4">
+        <div>
+          <h1 className="text-2xl font-bold tracking-tight">Build Exam</h1>
+          <p className="text-muted-foreground">Assemble questions for your exam.</p>
+        </div>
+        <ExamAssembly
+          examId={exam.id}
+          title={exam.title}
+          subject={exam.subject}
+          grade={exam.grade}
+          difficulty={exam.difficulty}
+          totalScore={exam.totalScore}
+          durationMin={exam.durationMin}
+          initialSelected={initialSelected}
+          initialStructure={initialStructure}
+          questionOptions={questionOptions}
+        />
       </div>
-      <ExamAssembly
-        examId={exam.id}
-        title={exam.title}
-        subject={exam.subject}
-        grade={exam.grade}
-        difficulty={exam.difficulty}
-        totalScore={exam.totalScore}
-        durationMin={exam.durationMin}
-        initialSelected={initialSelected}
-        initialStructure={initialStructure}
-        questionOptions={questionOptions}
-      />
-    </div>
+    </AiClientProvider>
   )
 }

src/app/(dashboard)/teacher/homework/submissions/[submissionId]/page.tsx

@@ -3,15 +3,46 @@ import { notFound } from "next/navigation"
 import { getHomeworkSubmissionDetails } from "@/modules/homework/data-access"
 import { HomeworkGradingView } from "@/modules/homework/components/homework-grading-view"
 import { formatDate } from "@/shared/lib/utils"
+import {
+  AiClientProvider,
+  type AiClientService,
+} from "@/modules/ai/context/ai-client-provider"
+import {
+  suggestGradingAction,
+  aiChatAction,
+  suggestSimilarQuestionsAction,
+  generateLessonContentAction,
+  generateQuestionVariantAction,
+  analyzeWeaknessAction,
+} from "@/modules/ai/actions"
 
 export const dynamic = "force-dynamic"
 
+/**
+ * 构建 AI 客户端服务（Server Action 引用集合）
+ *
+ * 通过 React Context 注入，客户端组件不直接 import actions，
+ * 遵循依赖注入模式，便于测试时替换为 mock。
+ */
+function createAiClientService(): AiClientService {
+  return {
+    chat: aiChatAction,
+    suggestSimilarQuestions: suggestSimilarQuestionsAction,
+    suggestGrading: suggestGradingAction,
+    generateLessonContent: generateLessonContentAction,
+    generateQuestionVariant: generateQuestionVariantAction,
+    analyzeWeakness: analyzeWeaknessAction,
+  }
+}
+
 export default async function HomeworkSubmissionGradingPage({ params }: { params: Promise<{ submissionId: string }> }): Promise<JSX.Element> {
   const { submissionId } = await params
   const submission = await getHomeworkSubmissionDetails(submissionId)
 
   if (!submission) return notFound()
 
+  const aiClientService = createAiClientService()
+
   return (
     <div className="flex h-full flex-col space-y-4 p-6">
       <div className="flex items-center justify-between">
@@ -29,17 +60,19 @@ export default async function HomeworkSubmissionGradingPage({ params }: { params
         </div>
       </div>
 
-      <HomeworkGradingView
-        submissionId={submission.id}
-        studentName={submission.studentName}
-        assignmentTitle={submission.assignmentTitle}
-        submittedAt={submission.submittedAt}
-        status={submission.status}
-        totalScore={submission.totalScore}
-        answers={submission.answers}
-        prevSubmissionId={submission.prevSubmissionId}
-        nextSubmissionId={submission.nextSubmissionId}
-      />
+      <AiClientProvider service={aiClientService}>
+        <HomeworkGradingView
+          submissionId={submission.id}
+          studentName={submission.studentName}
+          assignmentTitle={submission.assignmentTitle}
+          submittedAt={submission.submittedAt}
+          status={submission.status}
+          totalScore={submission.totalScore}
+          answers={submission.answers}
+          prevSubmissionId={submission.prevSubmissionId}
+          nextSubmissionId={submission.nextSubmissionId}
+        />
+      </AiClientProvider>
     </div>
   )
 }

src/app/(dashboard)/teacher/lesson-plans/[planId]/edit/page.tsx

@@ -1,12 +1,44 @@
 import type { JSX } from "react"
+import { Suspense } from "react"
 import { notFound } from "next/navigation"
 import { getLessonPlanById } from "@/modules/lesson-preparation/data-access"
 import { LessonPlanEditor } from "@/modules/lesson-preparation/components/lesson-plan-editor"
 import { getTeacherClasses } from "@/modules/classes/data-access"
+import { getTextbookById, getChaptersByTextbookId } from "@/modules/textbooks/data-access"
 import { getAuthContext } from "@/shared/lib/auth-guard"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+import {
+  AiClientProvider,
+  type AiClientService,
+} from "@/modules/ai/context/ai-client-provider"
+import {
+  aiChatAction,
+  suggestSimilarQuestionsAction,
+  suggestGradingAction,
+  generateLessonContentAction,
+  generateQuestionVariantAction,
+  analyzeWeaknessAction,
+} from "@/modules/ai/actions"
 
 export const dynamic = "force-dynamic"
 
+/**
+ * 构建 AI 客户端服务（Server Action 引用集合）
+ *
+ * 通过 React Context 注入，客户端组件不直接 import actions，
+ * 遵循依赖注入模式，便于测试时替换为 mock。
+ */
+function createAiClientService(): AiClientService {
+  return {
+    chat: aiChatAction,
+    suggestSimilarQuestions: suggestSimilarQuestionsAction,
+    suggestGrading: suggestGradingAction,
+    generateLessonContent: generateLessonContentAction,
+    generateQuestionVariant: generateQuestionVariantAction,
+    analyzeWeakness: analyzeWeaknessAction,
+  }
+}
+
 export default async function EditLessonPlanPage({
   params,
 }: {
@@ -23,16 +55,53 @@ export default async function EditLessonPlanPage({
 
   const classes = teacherClasses.map((c) => ({ id: c.id, name: c.name }))
 
+  // 拉取教材/章节标题用于工具栏显示
+  let textbookTitle: string | undefined
+  let chapterTitle: string | undefined
+  if (plan.textbookId) {
+    const textbook = await getTextbookById(plan.textbookId)
+    textbookTitle = textbook?.title
+    if (plan.chapterId) {
+      const chapters = await getChaptersByTextbookId(plan.textbookId)
+      const findChapter = (list: typeof chapters): typeof chapters[number] | undefined => {
+        for (const ch of list) {
+          if (ch.id === plan.chapterId) return ch
+          if (ch.children && ch.children.length > 0) {
+            const found = findChapter(ch.children as typeof chapters)
+            if (found) return found
+          }
+        }
+        return undefined
+      }
+      const chapter = findChapter(chapters)
+      chapterTitle = chapter?.title
+    }
+  }
+
+  const aiClientService = createAiClientService()
+
   return (
-    <div className="h-[calc(100vh-4rem)]">
-      <LessonPlanEditor
-        planId={plan.id}
-        initialTitle={plan.title}
-        initialDoc={plan.content}
-        textbookId={plan.textbookId ?? undefined}
-        chapterId={plan.chapterId ?? undefined}
-        classes={classes}
-      />
-    </div>
+    <AiClientProvider service={aiClientService}>
+      <div className="h-[calc(100vh-4rem)]">
+        <Suspense
+          fallback={
+            <div className="flex h-full items-center justify-center">
+              <Skeleton className="h-[80%] w-[80%]" />
+            </div>
+          }
+        >
+          <LessonPlanEditor
+            planId={plan.id}
+            initialTitle={plan.title}
+            initialDoc={plan.content}
+            textbookId={plan.textbookId ?? undefined}
+            chapterId={plan.chapterId ?? undefined}
+            textbookTitle={textbookTitle}
+            chapterTitle={chapterTitle}
+            classes={classes}
+          />
+        </Suspense>
+      </div>
+    </AiClientProvider>
   )
 }