[Feature] Add localization-ready structure by default

[ducbm051291]

Why

Generated apps should be ready for localization from day one instead of hardcoding user-facing strings in SwiftUI views.

Acceptance Criteria

• The template includes default localization resources.
• Starter screens use localized keys instead of hardcoded strings.
• The generated app can add new locales without changing the app structure.
• The pattern for localized strings is clear in the template.

Design

N/A

Resources

• Apple documentation for SwiftUI localization
• Existing starter flow screens in the template