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/trpc/query-client.ts

@@ -0,0 +1,25 @@
+import {
+  defaultShouldDehydrateQuery,
+  QueryClient,
+} from "@tanstack/react-query";
+import SuperJSON from "superjson";
+
+export const createQueryClient = () =>
+  new QueryClient({
+    defaultOptions: {
+      queries: {
+        // With SSR, we usually want to set some default staleTime
+        // above 0 to avoid refetching immediately on the client
+        staleTime: 30 * 1000,
+      },
+      dehydrate: {
+        serializeData: SuperJSON.serialize,
+        shouldDehydrateQuery: (query) =>
+          defaultShouldDehydrateQuery(query) ||
+          query.state.status === "pending",
+      },
+      hydrate: {
+        deserializeData: SuperJSON.deserialize,
+      },
+    },
+  });