fix: resolve post-merge issues in auxiliary_client and model flow

- Add missing `from agent.credential_pool import load_pool` import to
  auxiliary_client.py (introduced by the credential pool feature in main)
- Thread `args` through `select_provider_and_model(args=None)` so TLS
  options from `cmd_model` reach `_model_flow_nous`
- Mock `_require_tty` in test_cmd_model_forwards_nous_login_tls_options
  so it can run in non-interactive test environments

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hermes_cli/main.py

@@ -858,10 +858,10 @@ def cmd_setup(args):
 def cmd_model(args):
     """Select default model — starts with provider selection, then model picker."""
     _require_tty("model")
-    select_provider_and_model()
+    select_provider_and_model(args=args)
 
 
-def select_provider_and_model():
+def select_provider_and_model(args=None):
     """Core provider selection + model picking logic.
 
     Shared by ``cmd_model`` (``hermes model``) and the setup wizard