Redesign Property Management around a 12-column grid (matching the analytics dashboard) so partners control section and property width by columns (col3-col12) instead of abstract OneThird/Half/Full options, with automatic row wrapping and single-column collapse on narrow screens. Adds a live preview of the item create/edit form, wider content areas for large monitors, and an updated context menu for visible properties (Own Row / Shared Row toggle and Move To All Properties). Also includes clearer selected-vs-hover states for multi-select, Enable for Visible Properties checked by default to save an extra click when creating properties.