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/modules/dashboard/components/student-dashboard/student-dashboard-header.tsx

@@ -1,5 +1,3 @@
-"use client"
-
 import { DashboardGreetingHeader } from "../dashboard-greeting-header"
 
 interface StudentDashboardHeaderProps {

src/modules/dashboard/components/student-dashboard/student-grades-card.tsx

@@ -2,7 +2,7 @@
 
 import Link from "next/link"
 import { BarChart3 } from "lucide-react"
-import { useTranslations } from "next-intl"
+import { useTranslations, useLocale } from "next-intl"
 
 import { Button } from "@/shared/components/ui/button"
 import { ChartCardShell } from "@/shared/components/charts/chart-card-shell"
@@ -13,6 +13,7 @@ import type { StudentDashboardGradeProps } from "@/modules/homework/types"
 
 export function StudentGradesCard({ grades }: { grades: StudentDashboardGradeProps }) {
   const t = useTranslations("dashboard")
+  const locale = useLocale()
   const hasGradeTrend = grades.trend.length > 0
   const hasRecentGrades = grades.recent.length > 0
 
@@ -20,7 +21,7 @@ export function StudentGradesCard({ grades }: { grades: StudentDashboardGradePro
     title: item.assignmentTitle,
     score: Math.round(item.percentage),
     fullTitle: item.assignmentTitle,
-    submittedAt: formatDate(item.submittedAt),
+    submittedAt: formatDate(item.submittedAt, locale),
     rawScore: item.score,
     maxScore: item.maxScore,
   }))
@@ -102,7 +103,7 @@ export function StudentGradesCard({ grades }: { grades: StudentDashboardGradePro
                     <TableCell className="tabular-nums">
                       {r.score}/{r.maxScore} <span className="text-muted-foreground">({Math.round(r.percentage)}%)</span>
                     </TableCell>
-                    <TableCell className="text-muted-foreground">{formatDate(r.submittedAt)}</TableCell>
+                    <TableCell className="text-muted-foreground">{formatDate(r.submittedAt, locale)}</TableCell>
                   </TableRow>
                 ))}
               </TableBody>

src/modules/dashboard/components/student-dashboard/student-upcoming-assignments-card.tsx

@@ -1,6 +1,6 @@
 import Link from "next/link"
 import { PenTool } from "lucide-react"
-import { getTranslations } from "next-intl/server"
+import { getLocale, getTranslations } from "next-intl/server"
 
 import { Badge } from "@/shared/components/ui/badge"
 import { Button } from "@/shared/components/ui/button"
@@ -27,7 +27,7 @@ const getActionVariant = (status: string): "default" | "secondary" | "outline" =
   return "default"
 }
 
-const getDueUrgency = (dueAt: string | null) => {
+const getDueUrgency = (dueAt: string | null): "overdue" | "urgent" | "warning" | "normal" | null => {
   if (!dueAt) return null
   const now = new Date()
   const due = new Date(dueAt)
@@ -41,6 +41,7 @@ const getDueUrgency = (dueAt: string | null) => {
 
 export async function StudentUpcomingAssignmentsCard({ upcomingAssignments }: { upcomingAssignments: StudentHomeworkAssignmentListItem[] }) {
   const t = await getTranslations("dashboard")
+  const locale = await getLocale()
   const hasAssignments = upcomingAssignments.length > 0
 
   return (
@@ -60,6 +61,7 @@ export async function StudentUpcomingAssignmentsCard({ upcomingAssignments }: {
             icon={PenTool}
             title={t("empty.noAssignmentsStudent")}
             description={t("empty.noAssignmentsStudentDesc")}
+            action={{ label: t("quickActions.viewAll"), href: "/student/learning/assignments" }}
             className="border-none h-72"
           />
         ) : (
@@ -103,7 +105,7 @@ export async function StudentUpcomingAssignmentsCard({ upcomingAssignments }: {
                         !isGraded && urgency === "overdue" && "text-destructive font-medium",
                         !isGraded && urgency === "urgent" && "text-orange-500 font-medium"
                       )}>
-                        {a.dueAt ? formatDate(a.dueAt) : "-"}
+                        {a.dueAt ? formatDate(a.dueAt, locale) : "-"}
                       </TableCell>
                       <TableCell className="tabular-nums">{a.latestScore ?? "-"}</TableCell>
                       <TableCell className="text-right">