feat: Add JWT authentication to backend, configure frontend API client, fix streak layout

src/app/admin/students/[studentId]/page.tsx

@@ -1,5 +1,6 @@
 "use client"
 
+import { fetchWithAuth } from "@/lib/apiClient";
 import { useEffect, useState } from "react"
 import { useParams, useRouter } from "next/navigation"
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card"
@@ -46,7 +47,7 @@ export default function StudentKundliPage() {
   const [editExam, setEditExam] = useState("")
 
   useEffect(() => {
-    fetch(`/api/admin/students/${studentId}`)
+    fetchWithAuth(`/api/admin/students/${studentId}`)
       .then(r => { if (!r.ok) throw new Error("Not found"); return r.json() })
       .then(d => {
         setData(d)
@@ -62,7 +63,7 @@ export default function StudentKundliPage() {
   const handleSave = async () => {
     setSaving(true)
     try {
-      const res = await fetch(`/api/admin/students/${studentId}`, {
+      const res = await fetchWithAuth(`/api/admin/students/${studentId}`, {
         method: "PATCH",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
@@ -74,7 +75,7 @@ export default function StudentKundliPage() {
       })
       if (!res.ok) throw new Error("Failed to save")
       // Refresh data
-      const fresh = await fetch(`/api/admin/students/${studentId}`).then(r => r.json())
+      const fresh = await fetchWithAuth(`/api/admin/students/${studentId}`).then(r => r.json())
       setData(fresh)
       setEditing(false)
     } catch (e: any) {