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/react.tsx

@@ -0,0 +1,81 @@
+"use client";
+
+import { QueryClientProvider, type QueryClient } from "@tanstack/react-query";
+import { httpBatchStreamLink, loggerLink } from "@trpc/client";
+import { createTRPCReact } from "@trpc/react-query";
+import { type inferRouterInputs, type inferRouterOutputs } from "@trpc/server";
+import { useState } from "react";
+import SuperJSON from "superjson";
+import { SessionProvider } from "next-auth/react";
+
+import { type AppRouter } from "~/server/api/root";
+import { createQueryClient } from "./query-client";
+
+let clientQueryClientSingleton: QueryClient | undefined = undefined;
+const getQueryClient = () => {
+  if (typeof window === "undefined") {
+    // Server: always make a new query client
+    return createQueryClient();
+  }
+  // Browser: use singleton pattern to keep the same query client
+  clientQueryClientSingleton ??= createQueryClient();
+
+  return clientQueryClientSingleton;
+};
+
+export const api = createTRPCReact<AppRouter>();
+
+/**
+ * Inference helper for inputs.
+ *
+ * @example type HelloInput = RouterInputs['example']['hello']
+ */
+export type RouterInputs = inferRouterInputs<AppRouter>;
+
+/**
+ * Inference helper for outputs.
+ *
+ * @example type HelloOutput = RouterOutputs['example']['hello']
+ */
+export type RouterOutputs = inferRouterOutputs<AppRouter>;
+
+export function TRPCReactProvider(props: { children: React.ReactNode }) {
+  const queryClient = getQueryClient();
+
+  const [trpcClient] = useState(() =>
+    api.createClient({
+      links: [
+        loggerLink({
+          enabled: (op) =>
+            process.env.NODE_ENV === "development" ||
+            (op.direction === "down" && op.result instanceof Error),
+        }),
+        httpBatchStreamLink({
+          transformer: SuperJSON,
+          url: getBaseUrl() + "/api/trpc",
+          headers: () => {
+            const headers = new Headers();
+            headers.set("x-trpc-source", "nextjs-react");
+            return headers;
+          },
+        }),
+      ],
+    }),
+  );
+
+  return (
+    <SessionProvider>
+      <QueryClientProvider client={queryClient}>
+        <api.Provider client={trpcClient} queryClient={queryClient}>
+          {props.children}
+        </api.Provider>
+      </QueryClientProvider>
+    </SessionProvider>
+  );
+}
+
+function getBaseUrl() {
+  if (typeof window !== "undefined") return window.location.origin;
+  if (process.env.VERCEL_URL) return `https://${process.env.VERCEL_URL}`;
+  return `http://localhost:${process.env.PORT ?? 3000}`;
+}