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

src/app/dashboard/ai-coach/cbt-dpp/page.tsx

@@ -1,5 +1,6 @@
 "use client"
 
+import { fetchWithAuth } from "@/lib/apiClient";
 import { Button } from "@/components/ui/button"
 import { Card, CardContent } from "@/components/ui/card"
 import { BrainCircuit, Play, CheckCircle2, Download, Filter, Lock, FileText, Eye, ShieldAlert, X, Sparkles, Share2, Maximize2, Minimize2 } from "lucide-react"
@@ -25,14 +26,14 @@ export default function AIDailyPracticePage() {
       try {
         const pattern = user.target_exam || "JEE_Main";
         // Also fetch from the correct Next.js proxied route instead of localhost:8000
-        const res = await fetch(`/api/tests?type=DPS&exam_pattern=${pattern}`);
+        const res = await fetchWithAuth(`/api/tests?type=DPS&exam_pattern=${pattern}`);
         if (res.ok) {
           const data = await res.json()
           setDpps(data)
         }
         
         if (userId) {
-          const attemptsRes = await fetch(`/api/users/${userId}/attempts`);
+          const attemptsRes = await fetchWithAuth(`/api/users/${userId}/attempts`);
           if (attemptsRes.ok) {
             const attemptsData = await attemptsRes.json();
             setAttempts(attemptsData);

src/app/dashboard/ai-coach/page.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import { fetchWithAuth } from "@/lib/apiClient";
 import { useEffect, useState } from "react"
 import { MistakeHeatmap } from "@/components/AI/MistakeHeatmap"
 import { StudyPlanCard } from "@/components/AI/StudyPlanCard"
@@ -39,7 +40,7 @@ export default function AICoachDashboard() {
 
   useEffect(() => {
     if (!userLoading && userId) {
-      fetch(`/api/users/${userId}/stats`)
+      fetchWithAuth(`/api/users/${userId}/stats`)
         .then(res => res.ok ? res.json() : null)
         .then(data => setStats(data))
         .catch(() => setStats(null))