Add Google Client ID fetching in auth context and create auth config API route

app/api/auth/config/route.ts

@@ -0,0 +1,16 @@
+import { NextResponse } from "next/server"
+
+export const runtime = "nodejs"
+export const dynamic = "force-dynamic"
+
+export async function GET() {
+  const googleClientId =
+    (process.env.NEXT_PUBLIC_GOOGLE_CLIENT_ID || process.env.GOOGLE_CLIENT_ID || "").trim()
+
+  return NextResponse.json(
+    {
+      googleClientId,
+    },
+    { status: 200 },
+  )
+}