Add _light postfix to color resources for light theme

[XDdevv]

🎯 Goal

Add a _light postfix to color resources used in the light theme to make them consistent with the existing _dark colors and improve clarity when managing multiple themes.

🛠 Implementation details

• Renamed existing light theme colors to include the _light postfix.
• No changes to dark theme colors.
• This is purely a naming/refactor change to improve clarity and maintainability.

✍️ Explain examples

Before:

<color name="background">#F4EBF4</color>

After:

<color name="background_light">#F4EBF4</color>

Preparing a pull request for review

Ensure your change is properly formatted by running:

$ ./gradlew spotlessApply

Please correct any failures before requesting a review.