feat(sidebar): add integrated trigger button with mobile support

[nipsysdev]

Summary

• Add integrated trigger button support to Sidebar component
• Enhance SidebarTrigger with customizable props
• Update docs header for mobile-only trigger placement

Changes

packages/lsd/src/components/ui/sidebar/Sidebar.tsx

• Add showTrigger, triggerIconExpanded, triggerIconCollapsed, triggerClassName props
• Render SidebarTrigger inline when showTrigger is true
• Use CaretLeft/CaretRight icons as default expanded/collapsed indicators

packages/lsd/src/components/ui/sidebar/SidebarContent.tsx

• Add icon, text, iconClassName, textClassName props to SidebarTrigger
• Enable customization of trigger appearance

packages/lsd/src/components/ui/sidebar/types.ts

• Add TSDoc-documented types for new Sidebar and SidebarTrigger props

packages/lsd-docs/app/components/Header.tsx

• Show SidebarTrigger only on mobile (isMobile check)
• Adjust header layout for mobile vs desktop

packages/lsd-docs/app/components/sidebar/page.tsx

• Document all new props with usage examples