feat(app): add error/loading boundaries and update dashboard routes

- Add error.tsx and loading.tsx boundaries for admin, parent, student, teacher routes

- Add dashboard-error-fallback and dashboard-loading-skeleton components

- Add student/learning page, parent/leave routes, teacher textbook components

- Update existing app routes across auth, dashboard, and API endpoints

- Update proxy middleware and next-auth type declarations

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

@@ -1,15 +1,16 @@
-import type { JSX, ReactNode } from "react"
+import type { JSX } from "react"
 import { notFound } from "next/navigation"
 import { ArrowLeft } from "lucide-react"
 import Link from "next/link"
 import { getTranslations } from "next-intl/server"
 import { Button } from "@/shared/components/ui/button"
 import { Badge } from "@/shared/components/ui/badge"
-import { getTextbookById, getChaptersByTextbookId, getKnowledgePointsByTextbookId } from "@/modules/textbooks/data-access"
-import { TextbookReader, type TextbookReaderProps } from "@/modules/textbooks/components/textbook-reader"
+import { getTextbookById, getChaptersByTextbookId } from "@/modules/textbooks/data-access"
+import { TeacherTextbookReader } from "./_components/teacher-textbook-reader"
 import { TextbookSettingsDialog } from "@/modules/textbooks/components/textbook-settings-dialog"
-import { CreateQuestionDialog } from "@/modules/questions/components/create-question-dialog"
-import type { KnowledgePoint } from "@/modules/textbooks/types"
+import { getSubjectLabelKey, getGradeLabelKey } from "@/modules/textbooks/constants"
+import { requirePermission } from "@/shared/lib/auth-guard"
+import { Permissions } from "@/shared/types/permissions"
 
 export const dynamic = "force-dynamic"
 
@@ -18,38 +19,20 @@ export default async function TextbookDetailPage({
 }: {
   params: Promise<{ id: string }>
 }): Promise<JSX.Element> {
+  await requirePermission(Permissions.TEXTBOOK_READ)
+
   const { id } = await params
   const t = await getTranslations("textbooks")
 
-  const [textbook, chapters, knowledgePoints] = await Promise.all([
+  const [textbook, chapters] = await Promise.all([
     getTextbookById(id),
     getChaptersByTextbookId(id),
-    getKnowledgePointsByTextbookId(id),
   ])
 
   if (!textbook) {
     notFound()
   }
 
-  // P0-1 在页面层注入 questions 模块的 CreateQuestionDialog 实现
-  const renderQuestionCreator: TextbookReaderProps["renderQuestionCreator"] = ({
-    open,
-    onOpenChange,
-    targetKp,
-  }: {
-    open: boolean
-    onOpenChange: (open: boolean) => void
-    targetKp: KnowledgePoint | null
-  }): ReactNode => (
-    <CreateQuestionDialog
-      open={open}
-      onOpenChange={onOpenChange}
-      defaultKnowledgePointIds={targetKp ? [targetKp.id] : []}
-      defaultContent={targetKp ? `Please explain the knowledge point: ${targetKp.name}` : ""}
-      defaultType="text"
-    />
-  )
-
   return (
     <div className="flex flex-col h-[calc(100vh-4rem)] overflow-hidden">
       {/* Header / Nav (Fixed height) */}
@@ -62,9 +45,9 @@ export default async function TextbookDetailPage({
         </Button>
         <div className="flex-1 min-w-0">
           <div className="flex items-center gap-2 mb-1">
-            <Badge variant="outline">{textbook.subject}</Badge>
+            <Badge variant="outline">{t(`subject.${getSubjectLabelKey(textbook.subject)}`)}</Badge>
             <span className="text-xs text-muted-foreground uppercase tracking-wider font-medium">
-              {textbook.grade}
+              {textbook.grade ? t(`grade.${getGradeLabelKey(textbook.grade)}`) : ""}
             </span>
           </div>
           <h1 className="text-xl font-bold tracking-tight line-clamp-1">{textbook.title}</h1>
@@ -76,12 +59,7 @@ export default async function TextbookDetailPage({
 
       {/* Main Content Layout (Flex grow) */}
       <div className="flex-1 overflow-hidden pt-6">
-        <TextbookReader
-          chapters={chapters}
-          knowledgePoints={knowledgePoints}
-          textbookId={id}
-          renderQuestionCreator={renderQuestionCreator}
-        />
+        <TeacherTextbookReader chapters={chapters} textbookId={id} />
       </div>
     </div>
   )