fix: HERMES_PORTAL_BASE_URL env var ignored during Nous login

_login_nous() was passing pconfig.portal_base_url (hardcoded production
URL) as a fallback when no --portal-url CLI flag was given. This meant
_nous_device_code_login() received a truthy portal_base_url argument
and never reached the env var fallback chain.

Users setting HERMES_PORTAL_BASE_URL or NOUS_PORTAL_BASE_URL in .env
to point at a staging portal were silently ignored — login always went
to production.

Fix: pass None when no CLI flag is provided, letting the downstream
function properly check env vars before falling back to the default.

Fallback chain is now:
1. --portal-url CLI arg
2. HERMES_PORTAL_BASE_URL env var
3. NOUS_PORTAL_BASE_URL env var
4. DEFAULT_NOUS_PORTAL_URL (production)

Same fix applied to inference_base_url for consistency.

hermes_cli/auth.py

@@ -2577,8 +2577,8 @@ def _login_nous(args, pconfig: ProviderConfig) -> None:
 
     try:
         auth_state = _nous_device_code_login(
-            portal_base_url=getattr(args, "portal_url", None) or pconfig.portal_base_url,
-            inference_base_url=getattr(args, "inference_url", None) or pconfig.inference_base_url,
+            portal_base_url=getattr(args, "portal_url", None),
+            inference_base_url=getattr(args, "inference_url", None),
             client_id=getattr(args, "client_id", None) or pconfig.client_id,
             scope=getattr(args, "scope", None) or pconfig.scope,
             open_browser=not getattr(args, "no_browser", False),