Remove Stale Localizations and Standardize Keys with Underscores

Problem

• Leveral localizations are outdated, generating Xcode warnings. Have a look at Localizable.strings
• Inconsistent localization key naming: some keys lack underscores, making them more error prone when referenced in code.

Solution

• Remove stale localizations from Localizable.strings to clear Xcode warnings and improve maintainability.
• Convert existing localization keys to underscore format (e.g., 'USER_SETTINGS' instead of 'User Settings')

Additional context

No response

Code of Conduct

• I agree to follow this project's Code of Conduct and Contributing Guidelines