feat: update registry to use namespaced dependencies

- All registryDependencies now use @gc-solid/ namespace
- Enables automatic dependency resolution when PR is merged
- Users will only need to run one command to install components with all their dependencies

Example:
  npx shadcn@latest add @gc-solid/sidebar
  # Will automatically install @gc-solid/button, @gc-solid/separator, @gc-solid/sheet, etc.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: binnodon