feat(ai-chat): add toggle-widget support, auto focus input option and default model selection

[Rejdukien]

• Adds support for yasbc toggle-widget ai_chat
• Adds an auto focus input option, configured via yaml, defaults to false
• Add a default model selection, also configured via yaml, default: true added to the respective model. Only affects initial initialization, if the widget is opened, model/provider changed, closed and opened back up the default model doesn't affect it.
  Also, should more than one model be declared as default, first model is selected as default.

Just started using yasb, figured I'd implement the changes I'd like to see myself. Should make it easier to use the widget via hotkeys.

Tested behavior with "old" yaml before the change, no breaking changes from what I could see.

[Copilot]

Pull request overview

This PR adds three new features to the AI Chat widget to improve usability when controlling the widget via keyboard shortcuts:

• Toggle widget visibility via CLI command (yasbc toggle-widget ai_chat)
• Auto-focus input field option when chat window opens
• Default model selection for initial widget initialization

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/core/widgets/yasb/ai_chat.py	Implements toggle-widget CLI handling, auto-focus input functionality, and default model selection logic
src/core/widgets/base.py	Adds widget_config_name property to BaseWidget for identifying widgets in CLI commands
src/core/validation/widgets/yasb/ai_chat.py	Adds validation schemas for new auto_focus_input and default configuration options
src/core/utils/widget_builder.py	Sets widget_config_name on widget instances during construction
docs/widgets/(Widget)-Ai-Chat.md	Documents the new features and their configuration options

[Rejdukien]

I went ahead and made it possible to toggle specific instances of the widget by adding a widget_config_name attribute to the base widget, which gets populated by the widget builder. This name can be referenced when calling toggle-widget - at least for this widget, haven't touched the _handle_widget_cli method of other ones. Don't think it'd make much sense to have multiple launchpads, wallpaper managers or power menu widgets.
Figured it's not a bad idea, since technically it's possible to add multiple widgets of the same type.

[amnweb]

Interesting, Ai makes Ai widget xD

[Rejdukien]

Ayy, not gonna lie, for smaller changes in an unfamiliar codebase it's pretty decent - as long as you verify afterwards. 😛

[amnweb]

I will check all this when I have some free time, probably this weekend