feat: home page with MUI components

- Rewrote frontend from JSX to TypeScript (TSX)
- AppLayout with MUI AppBar, ThemeProvider, CssBaseline
- HomePage at / with dashboard metrics and recent updates
- MetricsPanel with 4 metric cards (total, interviews, offers, rejection rate)
- UpdateCard for each job update with status chip
- LoadingSkeleton during data fetch
- Error Alert on API failure
- Create New Job Application button navigating to /applications/new
- Vite proxy for /api → backend on :8000
- useDashboardData custom hook with concurrent fetch

Closes #2

api/jobs/views.py

@@ -0,0 +1,67 @@
+from django.db.models import Count, Q
+from rest_framework import permissions, viewsets
+from rest_framework.decorators import action
+from rest_framework.request import Request
+from rest_framework.response import Response
+
+from .models import JobApplication, JobUpdate
+from .serializers import (
+    DashboardMetricsSerializer,
+    JobApplicationSerializer,
+    JobUpdateSerializer,
+)
+
+
+class JobApplicationViewSet(viewsets.ModelViewSet):
+    queryset = JobApplication.objects.all().prefetch_related("updates")
+    serializer_class = JobApplicationSerializer
+    permission_classes = [permissions.AllowAny]
+
+
+class JobUpdateViewSet(viewsets.ModelViewSet):
+    queryset = JobUpdate.objects.select_related("job_application").all()
+    serializer_class = JobUpdateSerializer
+    permission_classes = [permissions.AllowAny]
+
+    @action(detail=False, methods=["get"])
+    def latest(self, request: Request) -> Response:
+        """Return the 3 most recent job updates with job info and metrics."""
+        updates = (
+            self.get_queryset()
+            .select_related("job_application")
+            .order_by("-created_at")[:3]
+        )
+        serializer = self.get_serializer(updates, many=True)
+        return Response(serializer.data)
+
+    @action(detail=False, methods=["get"])
+    def metrics(self, request: Request) -> Response:
+        """Return dashboard metrics: total apps, status breakdown, interview/offer counts."""
+        total = JobApplication.objects.count()
+        status_counts = dict(
+            JobApplication.objects.values("status")
+            .annotate(count=Count("id"))
+            .values_list("status", "count")
+        )
+        interview_count = JobApplication.objects.filter(
+            Q(status="INTERVIEW") | Q(status="OFFER")
+        ).count()
+        offer_count = JobApplication.objects.filter(status="OFFER").count()
+        rejection_rate = (
+            round(
+                status_counts.get("REJECTED", 0) / total * 100, 1
+            )
+            if total > 0
+            else 0.0
+        )
+
+        serializer = DashboardMetricsSerializer(
+            instance={
+                "total_applications": total,
+                "status_breakdown": status_counts,
+                "interviews_count": interview_count,
+                "offers_count": offer_count,
+                "rejection_rate": rejection_rate,
+            }
+        )
+        return Response(serializer.data)