[enhanced-readabilities] ON/OFF button text should use locale instead of hardcoded strings #631

The ON/OFF toggle buttons in the Spotlight component use hardcoded strings:

• text: 'ON'
• text: 'OFF'

These should use the locale system (like optionOn/optionOff already defined in locales) so that translations work properly.

Current behavior:
Setting custom optionOn/optionOff via app.provide(InjectionKey, {...}) does not change button text.

Expected behavior:
Button text should reflect the locale value (e.g., t('spotlight.optionOn') instead of 'ON').

Files affected:

• packages/vitepress-plugin-enhanced-readabilities/src/components/Spotlight.vue
• packages/vitepress-plugin-enhanced-readabilities/src/components/ScreenSpotlight.vue