chore: disable OTP/phone-validation at signup, fix next.config rewrite env bug, clean stale .next cache

next.config.ts

@@ -1,12 +1,16 @@
 import type { NextConfig } from "next";
 
+// Use NEXT_PUBLIC_API_URL for local dev (http://localhost:8000),
+// fall back to the Docker-internal service name for containerised deployments.
+const API_BASE = process.env.NEXT_PUBLIC_API_URL || "http://backend:8000";
+
 const nextConfig: NextConfig = {
   output: "standalone",
   async rewrites() {
     return [
       {
         source: "/api/:path*",
-        destination: "http://backend:8000/api/:path*",
+        destination: `${API_BASE}/api/:path*`,
       },
     ];
   },