- RightSidebar: added onCollapse prop and close button in header
- LeftSidebar: wired existing onCollapse prop in App.tsx
- CSS: show .leftbar-toggle and .rightbar-close on mobile
- Both buttons call setMobile{Left,Right}Open(false) to close overlays
- LeftSidebar/RightSidebar: added className prop for 'open' class
- Topbar: wired hamburger onClick + added mobile-drawer-toggle button for right panel
- App.tsx: added SettingsModal import/state/render, passed className props to sidebars
- styles.css: mobile sidebars now fixed slide-in overlays (translateX) instead of display:none
- ui.types.ts: added className to RightSidebarProps, onOpenLeftDrawer/onOpenRightDrawer to TopbarProps
- Tested at 390px viewport: both sidebars slide in correctly, transform verified via DOM