feat(teacher): 题库模块（QuestionBank）

工作内容

- 新增 /teacher/questions 页面，支持 Suspense/空状态/加载态

- 题库 CRUD Server Actions：创建/更新/递归删除子题，变更后 revalidatePath

- getQuestions 支持 q/type/difficulty/knowledgePointId 筛选与分页返回 meta

- UI：表格列/筛选器/创建编辑弹窗，content JSON 兼容组卷

- 更新中文设计文档：docs/design/004_question_bank_implementation.md

src/modules/questions/components/question-actions.tsx

@@ -2,6 +2,7 @@
 
 import { useState } from "react"
 import { MoreHorizontal, Pencil, Trash, Eye, Copy } from "lucide-react"
+import { useRouter } from "next/navigation"
 
 import { Button } from "@/shared/components/ui/button"
 import {
@@ -31,6 +32,7 @@ import {
 } from "@/shared/components/ui/dialog"
 
 import { Question } from "../types"
+import { deleteQuestionAction } from "../actions"
 import { CreateQuestionDialog } from "./create-question-dialog"
 import { toast } from "sonner"
 
@@ -39,6 +41,7 @@ interface QuestionActionsProps {
 }
 
 export function QuestionActions({ question }: QuestionActionsProps) {
+  const router = useRouter()
   const [showEditDialog, setShowEditDialog] = useState(false)
   const [showDeleteDialog, setShowDeleteDialog] = useState(false)
   const [showViewDialog, setShowViewDialog] = useState(false)
@@ -52,13 +55,17 @@ export function QuestionActions({ question }: QuestionActionsProps) {
   const handleDelete = async () => {
     setIsDeleting(true)
     try {
-      // Simulate API call
-      console.log("Deleting question:", question.id)
-      await new Promise(resolve => setTimeout(resolve, 1000))
-      toast.success("Question deleted successfully")
-      setShowDeleteDialog(false)
-    } catch (error) {
-      console.error(error)
+      const fd = new FormData()
+      fd.set("id", question.id)
+      const res = await deleteQuestionAction(undefined, fd)
+      if (res.success) {
+        toast.success("Question deleted successfully")
+        setShowDeleteDialog(false)
+        router.refresh()
+      } else {
+        toast.error(res.message || "Failed to delete question")
+      }
+    } catch {
       toast.error("Failed to delete question")
     } finally {
       setIsDeleting(false)
@@ -95,14 +102,12 @@ export function QuestionActions({ question }: QuestionActionsProps) {
         </DropdownMenuContent>
       </DropdownMenu>
 
-      {/* Edit Dialog */}
       <CreateQuestionDialog 
         open={showEditDialog} 
         onOpenChange={setShowEditDialog} 
         initialData={question}
       />
 
-      {/* Delete Confirmation Dialog */}
       <AlertDialog open={showDeleteDialog} onOpenChange={setShowDeleteDialog}>
         <AlertDialogContent>
           <AlertDialogHeader>
@@ -128,7 +133,6 @@ export function QuestionActions({ question }: QuestionActionsProps) {
         </AlertDialogContent>
       </AlertDialog>
 
-      {/* View Details Dialog (Simple Read-only View) */}
       <Dialog open={showViewDialog} onOpenChange={setShowViewDialog}>
         <DialogContent>
             <DialogHeader>
@@ -138,7 +142,7 @@ export function QuestionActions({ question }: QuestionActionsProps) {
             <div className="grid gap-4 py-4">
                 <div className="grid grid-cols-4 items-center gap-4">
                     <span className="font-medium">Type:</span>
-                    <span className="col-span-3 capitalize">{question.type.replace('_', ' ')}</span>
+                    <span className="col-span-3 capitalize">{question.type.replaceAll("_", " ")}</span>
                 </div>
                 <div className="grid grid-cols-4 items-center gap-4">
                     <span className="font-medium">Difficulty:</span>
@@ -147,17 +151,17 @@ export function QuestionActions({ question }: QuestionActionsProps) {
                 <div className="grid grid-cols-4 items-start gap-4">
                     <span className="font-medium pt-1">Content:</span>
                     <div className="col-span-3 rounded-md bg-muted p-2 text-sm">
-                        {typeof question.content === 'string' ? question.content : JSON.stringify(question.content, null, 2)}
+                        {typeof question.content === "string"
+                          ? question.content
+                          : JSON.stringify(question.content, null, 2)}
                     </div>
                 </div>
-                 {/* Show Author if exists */}
                  {question.author && (
                      <div className="grid grid-cols-4 items-center gap-4">
                         <span className="font-medium">Author:</span>
                         <span className="col-span-3">{question.author.name || "Unknown"}</span>
                     </div>
                  )}
-                 {/* Show Knowledge Points */}
                  {question.knowledgePoints && question.knowledgePoints.length > 0 && (
                      <div className="grid grid-cols-4 items-center gap-4">
                         <span className="font-medium">Tags:</span>