refactor: widget_onoff to input-group, webcam layout, vmbpy local whl

- widget_onoff: converted from d-flex to input-group+span.status-container
- widget_standard/shutter/render_info: added font-monospace to var badges
- ui-core: simplified applyVarStatusStyles (remove class overrides)
- webcam_panel: restructured layout to match original (figure/figcaption/hgroup)
- control_panel: removed dead camera_windowing macro
- synoptic_panel: converted Jinja comment to HTML comment
- pyproject.toml: vmbpy from local whl (lib/), version 0.5.1
- .gitignore: unblock lib/ to track vmbpy whl

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>