fix: add explicit type annotations for callback params losing contextual typing (#2815)

When @ariakit/react updates its internal module structure (e.g. from
@ariakit/react-core to @ariakit/react-components), contextual typing
from external library component props can break, causing TS7006
'Parameter implicitly has an any type' errors in the Fresh Install
Tests CI workflow.

Add explicit type annotations to 5 callback parameters that depend on
external library types for inference:

- packages/ariakit/src/panel/Panel.tsx: setActiveId callback
- packages/ariakit/src/toolbar/ToolbarButton.tsx: onMouseDown callback
- packages/ariakit/src/panel/PanelFileInput.tsx: onChange callback
- packages/ariakit/src/badge/Badge.tsx: onClick callback
- packages/xl-ai/src/components/AIMenu/AIMenuController.tsx: outsidePress callback

All annotations use React/DOM built-in types (MouseEvent, ChangeEvent)
rather than library-specific types, making them resilient to future
dependency updates.