chore: import upstream snapshot with attribution

apps/sim/lib/auth/auth-client.ts

@@ -0,0 +1,65 @@
+import { useContext } from 'react'
+import { ssoClient } from '@better-auth/sso/client'
+import { stripeClient } from '@better-auth/stripe/client'
+import {
+  adminClient,
+  customSessionClient,
+  emailOTPClient,
+  genericOAuthClient,
+  organizationClient,
+} from 'better-auth/client/plugins'
+import { createAuthClient } from 'better-auth/react'
+import type { auth } from '@/lib/auth'
+import { env } from '@/lib/core/config/env'
+import { isBillingEnabled, isOrganizationsEnabled } from '@/lib/core/config/env-flags'
+import { getBaseUrl, getBrowserOrigin } from '@/lib/core/utils/urls'
+import { SessionContext, type SessionHookResult } from '@/app/_shell/providers/session-provider'
+
+function getAuthBaseUrl(): string {
+  return getBrowserOrigin() ?? getBaseUrl()
+}
+
+export const client = createAuthClient({
+  baseURL: getAuthBaseUrl(),
+  plugins: [
+    adminClient(),
+    emailOTPClient(),
+    genericOAuthClient(),
+    customSessionClient<typeof auth>(),
+    ...(isBillingEnabled
+      ? [
+          stripeClient({
+            subscription: true, // Enable subscription management
+          }),
+        ]
+      : []),
+    ...(isOrganizationsEnabled ? [organizationClient()] : []),
+    ...(env.NEXT_PUBLIC_SSO_ENABLED ? [ssoClient()] : []),
+  ],
+})
+
+export function useSession(): SessionHookResult {
+  const ctx = useContext(SessionContext)
+  if (!ctx) {
+    throw new Error(
+      'SessionProvider is not mounted. Wrap your app with <SessionProvider> in app/layout.tsx.'
+    )
+  }
+  return ctx
+}
+
+export const useActiveOrganization = isOrganizationsEnabled
+  ? client.useActiveOrganization
+  : () => ({ data: undefined, isPending: false, error: null })
+
+export const useSubscription = () => {
+  return {
+    list: client.subscription?.list,
+    upgrade: client.subscription?.upgrade,
+    cancel: client.subscription?.cancel,
+    restore: client.subscription?.restore,
+  }
+}
+
+const { signIn, signUp, signOut } = client
+export { signOut }