hermes config set model.aliases.xxx commands write to the model.aliases
nested key, but _load_direct_aliases() only read from the top-level
model_aliases key. This meant aliases set via hermes config set were
invisible to the /model command, and unrecognised inputs fell through
to the DeepSeek normaliser which mapped everything to deepseek-chat.
Add a second pass in _load_direct_aliases() that reads model.aliases
and converts string-value entries (provider/model format) into
DirectAlias objects. The provider is parsed from the slash prefix;
if no slash, the current default provider from config is used.
Also prevent simple aliases from overriding explicit model_aliases
dict entries when both exist.
34c6f93496