feat: add UI component files and navigation structure

Added various UI components and navigation elements including:
- Section cards and selection components
- Social icon SVGs with horizontal/vertical text variants
- Table, tabs, and toggle components
- Site header and sidebar components
- Tooltip and unauthorized page
- Project configuration files (tsconfig.json)
- Route handlers for health checks
- Utility and hook functions for mobile responsiveness

app/not-found.tsx

@@ -0,0 +1,37 @@
+"use client"
+import { ArrowLeft, FileQuestion, Home } from "lucide-react"
+import Link from "next/link"
+import { Button } from "@/components/ui/button"
+import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from "@/components/ui/card"
+
+export default function NotFound() {
+  return (
+    <div className="flex min-h-[80vh] items-center justify-center">
+      <Card className="max-w-md">
+        <CardHeader>
+          <div className="flex items-center gap-2">
+            <FileQuestion className="text-muted-foreground h-6 w-6" />
+            <CardTitle className="text-2xl">Page Not Found</CardTitle>
+          </div>
+          <CardDescription>We couldn't find the page you were looking for</CardDescription>
+        </CardHeader>
+        <CardContent className="text-muted-foreground">
+          <p>The page you requested doesn't exist or may have been moved.</p>
+          <div className="border-muted-foreground/20 mt-4 border-l-4 pl-4 text-sm italic">Error 404</div>
+        </CardContent>
+        <CardFooter className="flex justify-between">
+          <Button variant="outline" onClick={() => window.history.back()}>
+            <ArrowLeft className="mr-2 h-4 w-4" />
+            Go Back
+          </Button>
+          <Button asChild>
+            <Link href="/">
+              <Home className="mr-2 h-4 w-4" />
+              Return Home
+            </Link>
+          </Button>
+        </CardFooter>
+      </Card>
+    </div>
+  )
+}