feat: add ContentOnlyLayout and defaultOpen prop to SidebarLayout

[IzumiSy]

Summary

Add options to control sidebar layout behavior:

1. ContentOnlyLayout — A new layout component for screens that don't need a sidebar (e.g., kiosk mode, embedded views). Renders only the route outlet with minimal wrapper styling.

2. SidebarLayout defaultOpen prop — Controls whether the sidebar is initially expanded or collapsed.

Usage

import { SidebarLayout, ContentOnlyLayout } from "@tailor-platform/app-shell";

// Sidebar-less layout for kiosk or embedded screens
<ContentOnlyLayout />

// With custom content wrapper
<ContentOnlyLayout>
  {({ Outlet }) => (
    <>
      <CustomHeader />
      <Outlet />
    </>
  )}
</ContentOnlyLayout>

// Sidebar collapsed by default
<SidebarLayout defaultOpen={false} />

Changes

• packages/core/src/components/content-only-layout.tsx — New ContentOnlyLayout component
• packages/core/src/components/sidebar/sidebar-layout.tsx — Add defaultOpen prop to SidebarLayoutProps, pass it to SidebarProvider
• packages/core/src/index.ts — Export ContentOnlyLayout and ContentOnlyLayoutProps