feat(admin-ui): improve mobile layout

[VargaJoe]

Summary

This PR improves the Admin UI mobile experience while keeping the desktop layout intact.

Main changes:

• Adds a mobile-friendly content explorer layout with a collapsible content tree drawer.
• Improves mobile grid/content navigation and row tapping.
• Makes breadcrumbs compact on mobile so action buttons remain usable.
• Tightens mobile tree item spacing and prevents icon/text wrapping.
• Collapses the command palette to a search icon on mobile, opening a full-width search panel when tapped.
• Hides the repository URL on mobile to reduce header crowding.
• Adds an env-controlled option to hide the top view-options menu.
• Fixes Docker dev server stability and WebSocket URL handling for externally mapped ports.

Configuration

New/updated dev env options:

• DISABLE_DEV_RELOAD=true
• DISABLE_VIEW_OPTIONS_MENU=false
• WEBPACK_DEV_SERVER_CLIENT_WEB_SOCKET_URL=auto://0.0.0.0:0/ws

Verification

• npx --yes yarn@1.22.22 workspace @app/sensenet build:snauth
• docker compose -f .\docker-compose.dev.yml up -d --build
• Docker dev compile completed with webpack 5.75.0 compiled successfully and No issues found.

Known remaining warnings are pre-existing asset-size and Browserslist warnings.