fix: update user fields to match schema

- Replace firstName/lastName with name field in users API route
- Update user formatting in UsersTab component
- Add email fallback when name is not available

src/app/dashboard/studies/[id]/page.tsx

@@ -0,0 +1,172 @@
+'use client';
+
+import { useEffect, useState } from "react";
+import { useParams } from "next/navigation";
+import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "~/components/ui/card";
+import { Button } from "~/components/ui/button";
+import { 
+  Users, 
+  FileText, 
+  BarChart, 
+  PlayCircle,
+  Plus,
+  Settings2
+} from "lucide-react";
+import { useToast } from "~/hooks/use-toast";
+import Link from "next/link";
+
+interface StudyStats {
+  participantCount: number;
+  completedTrialsCount: number;
+  pendingFormsCount: number;
+}
+
+export default function StudyDashboard() {
+  const [stats, setStats] = useState<StudyStats>({
+    participantCount: 0,
+    completedTrialsCount: 0,
+    pendingFormsCount: 0,
+  });
+  const [loading, setLoading] = useState(true);
+  const { id } = useParams();
+  const { toast } = useToast();
+
+  useEffect(() => {
+    fetchStudyStats();
+  }, [id]);
+
+  const fetchStudyStats = async () => {
+    try {
+      const response = await fetch(`/api/studies/${id}/stats`);
+      if (!response.ok) throw new Error("Failed to fetch study statistics");
+      const data = await response.json();
+      setStats(data.data);
+    } catch (error) {
+      console.error("Error fetching study stats:", error);
+      toast({
+        title: "Error",
+        description: "Failed to load study statistics",
+        variant: "destructive",
+      });
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  if (loading) {
+    return (
+      <div className="flex items-center justify-center min-h-[400px]">
+        <div className="animate-spin h-8 w-8 border-4 border-primary border-t-transparent rounded-full" />
+      </div>
+    );
+  }
+
+  return (
+    <div className="space-y-6">
+      <div className="grid gap-4 md:grid-cols-3">
+        <Card>
+          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+            <CardTitle className="text-sm font-medium">Participants</CardTitle>
+            <Users className="h-4 w-4 text-muted-foreground" />
+          </CardHeader>
+          <CardContent>
+            <div className="text-2xl font-bold">{stats.participantCount}</div>
+            <p className="text-xs text-muted-foreground">Total participants enrolled</p>
+          </CardContent>
+        </Card>
+
+        <Card>
+          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+            <CardTitle className="text-sm font-medium">Completed Trials</CardTitle>
+            <PlayCircle className="h-4 w-4 text-muted-foreground" />
+          </CardHeader>
+          <CardContent>
+            <div className="text-2xl font-bold">{stats.completedTrialsCount}</div>
+            <p className="text-xs text-muted-foreground">Successfully completed trials</p>
+          </CardContent>
+        </Card>
+
+        <Card>
+          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+            <CardTitle className="text-sm font-medium">Pending Forms</CardTitle>
+            <FileText className="h-4 w-4 text-muted-foreground" />
+          </CardHeader>
+          <CardContent>
+            <div className="text-2xl font-bold">{stats.pendingFormsCount}</div>
+            <p className="text-xs text-muted-foreground">Forms awaiting completion</p>
+          </CardContent>
+        </Card>
+      </div>
+
+      <div className="grid gap-4 md:grid-cols-2">
+        <Card>
+          <CardHeader>
+            <CardTitle>Quick Actions</CardTitle>
+            <CardDescription>Common tasks for this study</CardDescription>
+          </CardHeader>
+          <CardContent className="space-y-2">
+            <Button
+              variant="outline"
+              className="w-full justify-start"
+              asChild
+            >
+              <Link href={`/dashboard/studies/${id}/participants/new`}>
+                <Plus className="mr-2 h-4 w-4" />
+                Add Participant
+              </Link>
+            </Button>
+            <Button
+              variant="outline"
+              className="w-full justify-start"
+              asChild
+            >
+              <Link href={`/dashboard/studies/${id}/trials/new`}>
+                <PlayCircle className="mr-2 h-4 w-4" />
+                Start New Trial
+              </Link>
+            </Button>
+            <Button
+              variant="outline"
+              className="w-full justify-start"
+              asChild
+            >
+              <Link href={`/dashboard/studies/${id}/forms/new`}>
+                <FileText className="mr-2 h-4 w-4" />
+                Create Form
+              </Link>
+            </Button>
+          </CardContent>
+        </Card>
+
+        <Card>
+          <CardHeader>
+            <CardTitle>Recent Activity</CardTitle>
+            <CardDescription>Latest updates and changes</CardDescription>
+          </CardHeader>
+          <CardContent className="space-y-2">
+            <Button
+              variant="outline"
+              className="w-full justify-start"
+              asChild
+            >
+              <Link href={`/dashboard/studies/${id}/analysis`}>
+                <BarChart className="mr-2 h-4 w-4" />
+                View Analytics
+              </Link>
+            </Button>
+            <Button
+              variant="outline"
+              className="w-full justify-start"
+              asChild
+            >
+              <Link href={`/dashboard/studies/${id}/settings`}>
+                <Settings2 className="mr-2 h-4 w-4" />
+                Study Settings
+              </Link>
+            </Button>
+          </CardContent>
+        </Card>
+      </div>
+    </div>
+  );
+}