feat(admin): add RoleBadge component and integrate it in user management views

- add new RoleBadge shared component for consistent role display
- export RoleBadge from shared components index
- replace inline Badge usage with RoleBadge in UsersPage role column
- use RoleBadge via renderTag prop in UserEditModal role TagInput
- simplify TagInput Pill to a generic unstyled pill, removing color logic

src/shared/components/index.js

@@ -1,5 +1,6 @@
 // Template components exports
 export { default as Badge, StatusBadge, TypeBadge } from './Badge';
+export { default as RoleBadge } from './RoleBadge';
 export { default as Button } from './Button';
 export { default as Card } from './Card';
 export { default as Input } from './Input';