feat: implement complete invoicing application with CSV import and PDF export

- Add comprehensive CSV import system with drag-and-drop upload and validation
- Create UniversalTable component with advanced filtering, searching, and batch actions
- Implement invoice management (view, edit, delete) with professional PDF export
- Add client management with full CRUD operations
- Set up authentication with NextAuth.js and email/password login
- Configure database schema with users, clients, invoices, and invoice_items tables
- Build responsive UI with shadcn/ui components and emerald branding
- Add type-safe API layer with tRPC and Zod validation
- Include proper error handling and user feedback with toast notifications
- Set up development environment with Bun, TypeScript, and Tailwind CSS

src/app/dashboard/invoices/page.tsx

@@ -0,0 +1,58 @@
+import Link from "next/link";
+import { auth } from "~/server/auth";
+import { api, HydrateClient } from "~/trpc/server";
+import { Button } from "~/components/ui/button";
+import { UniversalTable } from "~/components/ui/universal-table";
+import { Plus, Upload } from "lucide-react";
+
+export default async function InvoicesPage() {
+  const session = await auth();
+
+  if (!session?.user) {
+    return (
+      <div className="flex min-h-screen items-center justify-center bg-gradient-to-br from-emerald-50 via-white to-teal-50">
+        <div className="text-center">
+          <h1 className="text-4xl font-bold mb-4 bg-gradient-to-r from-emerald-600 to-teal-600 bg-clip-text text-transparent">Access Denied</h1>
+          <p className="text-muted-foreground mb-8">Please sign in to view invoices</p>
+          <Link href="/api/auth/signin">
+            <Button 
+              size="lg"
+              className="bg-gradient-to-r from-emerald-600 to-teal-600 hover:from-emerald-700 hover:to-teal-700 text-white font-medium shadow-lg hover:shadow-xl transition-all duration-200"
+            >
+              Sign In
+            </Button>
+          </Link>
+        </div>
+      </div>
+    );
+  }
+
+  // Prefetch invoices data
+  void api.invoices.getAll.prefetch();
+
+  return (
+    <div>
+      <div className="flex flex-col md:flex-row md:items-center md:justify-between mb-8 gap-4">
+        <div>
+          <h1 className="text-3xl font-bold bg-gradient-to-r from-emerald-600 to-teal-600 bg-clip-text text-transparent">Invoices</h1>
+          <p className="text-gray-600 mt-1 text-lg">Manage your invoices and payments.</p>
+        </div>
+        <div className="flex gap-3">
+          <Button asChild variant="outline" size="lg" className="bg-white/80 border-gray-200 hover:bg-gray-50 text-gray-700 font-medium shadow-lg hover:shadow-xl">
+            <Link href="/dashboard/invoices/import">
+              <Upload className="mr-2 h-5 w-5" /> Import CSV
+            </Link>
+          </Button>
+          <Button asChild size="lg" className="bg-gradient-to-r from-emerald-600 to-teal-600 hover:from-emerald-700 hover:to-teal-700 text-white font-medium shadow-lg hover:shadow-xl">
+            <Link href="/dashboard/invoices/new">
+              <Plus className="mr-2 h-5 w-5" /> Add Invoice
+            </Link>
+          </Button>
+        </div>
+      </div>
+      <HydrateClient>
+        <UniversalTable resource="invoices" />
+      </HydrateClient>
+    </div>
+  );
+}