fix(auth): revert SUPABASE_INTERNAL_URL — cookie name mismatch

Browser creates cookies keyed by the external hostname (sb-myeasycms-*),
but server was using SUPABASE_INTERNAL_URL (sb-supabase-kong-*) — different
keys = server can't find the session = infinite 'please wait' after login.

Both client and server now use the same NEXT_PUBLIC_SUPABASE_URL (external
domain). The SSR reaches Supabase via Traefik → Kong which works fine.

packages/supabase/src/get-supabase-client-keys.ts

@@ -2,18 +2,8 @@ import * as z from 'zod';
 
 /**
  * Returns and validates the Supabase client keys from the environment.
- *
- * On the server, prefers SUPABASE_INTERNAL_URL (Docker-internal)
- * over NEXT_PUBLIC_SUPABASE_URL (external domain) to avoid
- * hairpin NAT / DNS issues in containerized deployments.
  */
 export function getSupabaseClientKeys() {
-  const isServer = typeof window === 'undefined';
-
-  const url = isServer
-    ? (process.env.SUPABASE_INTERNAL_URL || process.env.NEXT_PUBLIC_SUPABASE_URL)
-    : process.env.NEXT_PUBLIC_SUPABASE_URL;
-
   return z
     .object({
       url: z.string({
@@ -24,7 +14,7 @@ export function getSupabaseClientKeys() {
       }),
     })
     .parse({
-      url,
+      url: process.env.NEXT_PUBLIC_SUPABASE_URL,
       publicKey: process.env.NEXT_PUBLIC_SUPABASE_PUBLIC_KEY,
     });
 }