Add Next.js client app with Prisma and auth

Introduce a new 'client' Next.js app scaffold: configuration files (next.config.ts, eslint.config.mjs, postcss, tsconfig), Prisma config and schema, app routes including NextAuth API and server actions, session/provider utilities, proxy, public assets, README and .gitignore. Also add IDE project files under .idea and a root README to initialize the repository structure for development.

client/src/lib/SessionProvider.tsx

@@ -0,0 +1,17 @@
+"use client"
+import { ReactNode } from "react";
+import { SessionProvider } from "next-auth/react";
+
+interface ProvidersProps {
+  children: ReactNode;
+}
+
+const Providers = ({ children }: ProvidersProps) => {
+  return (
+    <SessionProvider>
+      {children}
+    </SessionProvider>
+  );
+};
+
+export default Providers;