ui: don't reload a loading model on select, prefer it in pre-selection (#31326)
* ui: don't reload a loading model on select, prefer it in pre-selection
Assisted-by: Claude (Opus 5.5 Medium)
* ui: skip hidden models in automatic model selection
Assisted-by: Claude (Opus 5.5 Medium)
* ui: don't count a model being unloaded as loading
Assisted-by: Claude (Opus 5.5 Medium)