feat: #1224 framework wide UI font scaling and per area scale override

[funkosaur]

Description

Resolves the small-text concern raised in discussion #1224 . Made the existing fontSizeScaleUI setting actually framework-wide, and introduced three optional per-area scales on top so menus, dialogs, and notifications can each be tuned independently without affecting the rest of the UI.

Changes

• Moved fontSizeScaleUI application into FXGLUIFactoryServiceProvider at the single font-construction chokepoint, so every piece of UI routed through getUIFactoryService() now scales: menus, buttons, mini-games, dev console, inventory, cutscenes, loading screen, plus user code that uses the factory.
• Added three per-area scales to GameSettings, each defaulting to 1.0 and multiplied on top of fontSizeScaleUI:
  • fontSizeScaleMenu
  • fontSizeScaleDialog
  • fontSizeScaleNotification
• Wired fontSizeScaleDialog into FXGLDialogFactoryServiceProvider.
• Wired fontSizeScaleNotification into NotificationServiceProvider, alongside the existing fontSizeScaleUI injection, both are applied because the notification view bypasses UIFactoryService.
• Added a fontSize: Double field to NotificationView and switched XboxNotificationView from hardcoded Font.font(18.0) to Font.font(fontSize) inside playInAnimation().
• Added a menuScale computed property to FXGLDefaultMenu reading getSettings().fontSizeScaleMenu.
• KDoc on each new setting documents the layering: effective_size = raw * fontSizeScaleUI * fontSizeScaleArea.

Backward-compatible: all new fields default to 1.0. Existing user code that only touches fontSizeScaleUI continues to work; what changes is that fontSizeScaleUI now affects more UI than it used to.