Imrovements in model management

### Describe the feature or problem you'd like to solve

Quality of live improvments in choosing llm model

### Proposed solution

1. Add option to hide some models from /models (might be exclusion list in config file, no ui needed). There are too many now and some I will never use.
2. Add keyboard shortcut to change between models (like the one tfor plan/implement mode). Sometimes I'm in the middle of typing prompt and realize wrong model is active, have to copy prompt to clipbard, choose model, paste etc.
3. Add shorter names for models for `/model` command. I switch usually between Opus/Sonnet and claude-sonet-4.5 is a lot of typing. Might be not needed if 1 & 2 are available.

### Example prompts or workflows

_No response_

### Additional context

_No response_