Create React Feature

When creating a feature:

1. Create it under src/features/<feature-name>/.
2. Allowed subfolders:
   • pages
   • components
   • api
   • hooks
   • store
   • types
   • utils
3. Do not create barrel files.
4. Use @ imports for non-colocated app imports.
5. Relative imports are allowed only for colocated siblings such as CSS modules and same-folder feature-private files.
6. Do not create cross-feature imports.
7. Keep page components thin.
8. Keep page and parent components responsible for layout and spacing.
9. Child components must not control outer spacing.
10. Do not introduce useEffect unless there is no simpler alternative.
11. Keep route registration centralized in src/core/router/; do not create route registration files inside feature folders.
12. Replace magic numbers with well-named constants or shared helpers (for durations use src/shared/utils/time/).