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)/student/schedule/page.tsx

@@ -5,11 +5,10 @@ import { getCurrentStudentUser } from "@/modules/users/data-access"
 import { StudentScheduleFilters } from "@/modules/student/components/student-schedule-filters"
 import { StudentScheduleView } from "@/modules/student/components/student-schedule-view"
 import { EmptyState } from "@/shared/components/ui/empty-state"
+import { getParam, type SearchParams } from "@/shared/lib/search-params"
 
 export const dynamic = "force-dynamic"
 
-type SearchParams = { [key: string]: string | string[] | undefined }
-
 export default async function StudentSchedulePage({
   searchParams,
 }: {
@@ -18,7 +17,7 @@ export default async function StudentSchedulePage({
   const student = await getCurrentStudentUser()
   if (!student) {
     return (
-      <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
+      <div className="space-y-8">
         <div>
           <h2 className="text-2xl font-bold tracking-tight">Schedule</h2>
           <p className="text-muted-foreground">Your weekly timetable.</p>
@@ -34,18 +33,12 @@ export default async function StudentSchedulePage({
     getStudentSchedule(student.id),
   ])
 
-  const classIdParam = sp.classId
-  const resolveClassId = (param: string | string[] | undefined): string => {
-    if (typeof param === "string") return param
-    if (Array.isArray(param)) return param[0] ?? "all"
-    return "all"
-  }
-  const classId = resolveClassId(classIdParam)
+  const classId = getParam(sp, "classId") ?? "all"
   const filteredItems =
     classId !== "all" ? schedule.filter((s) => s.classId === classId) : schedule
 
   return (
-    <div className="flex h-full flex-col space-y-8 p-8">
+    <div className="space-y-8">
       <div className="flex flex-col justify-between gap-4 md:flex-row md:items-center">
         <div>
           <h2 className="text-2xl font-bold tracking-tight">Schedule</h2>