Users can now select models with multiple slashes like 'openrouter/google/gemini-2.5-pro'
in the TUI. Previously the TUI would only parse the first two parts of the model
path, showing 'Invalid model openrouter/google' for nested models.
Users can now press F2 to cycle forward and Shift+F2 to cycle backward through their recently used models, making it faster to switch between commonly used AI models without opening the model selection dialog.
- Add KVProvider context for storing user preferences like theme and warnings
- Update theme context to use KV storage instead of sync config
- Move openrouter warning to persistent KV storage
- Refactor theme selection to persist user choice across sessions