The get_available_models() function only handled dict-format models
(`{model_id: {}}`) for custom_providers entries, silently dropping
models specified as YAML lists (`[model1, model2]`) or list of dicts
(`[{id: ..., label: ...}]`).
This caused users who define their custom providers with list-format
model declarations to see zero or incomplete model entries in both
Settings → Preferences → Default Model dropdown and the chat
interface model picker.
The fix adds an `elif isinstance(_cp_models_dict, list)` branch with
support for three list sub-formats:
- Plain string list: `models: [m1, m2]`
- Dict list: `models: [{id: m1, label: ...}]`
- Mixed: `models: [m1, {id: m2}]`
Refs: hermes-agent issue where YAML list models were invisible
f82a763dfb