implement better-auth auth with postgres and route protection

lib/auth-client.ts

@@ -0,0 +1,14 @@
+import { createAuthClient } from 'better-auth/react';
+import { adminClient, magicLinkClient, organizationClient } from 'better-auth/client/plugins';
+import { resolveApiBaseURL } from '@/lib/runtime-url';
+
+const baseURL = resolveApiBaseURL(process.env.NEXT_PUBLIC_API_URL);
+
+export const authClient = createAuthClient({
+  baseURL: baseURL || undefined,
+  plugins: [
+    adminClient(),
+    magicLinkClient(),
+    organizationClient()
+  ]
+});