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/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>
   )
 }