fix(cli): guard .strip() against None values from YAML config (#3552)

dict.get(key, default) only returns default when key is ABSENT.
When YAML has 'key:' with no value, it parses as None — .get()
returns None, then .strip() crashes with AttributeError.

Use (x or '') pattern to handle both missing and null cases.


Salvaged from PR #3217.

Co-authored-by: erosika <erosika@users.noreply.github.com>

hermes_cli/main.py

@@ -832,8 +832,8 @@ def cmd_model(args):
         for entry in custom_providers_cfg:
             if not isinstance(entry, dict):
                 continue
-            name = entry.get("name", "").strip()
-            base_url = entry.get("base_url", "").strip()
+            name = (entry.get("name") or "").strip()
+            base_url = (entry.get("base_url") or "").strip()
             if not name or not base_url:
                 continue
             # Generate a stable key from the name