* fix: zone grid snapping, shelf position panel, deselect on item placement - Zone tool reads the editor's gridSnapStep (0.5/0.25/0.1/0.05) instead of a hardcoded 0.5 for both cursor move and click snapping. - Shelf inspector gains a Position group (vec3 X/Y/Z sliders), matching the item panel. - Item catalog clears the viewer selection before arming placement so shortcuts (rotate & co) don't hit both the ghost and the selected node. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * refactor: move level display naming into @pascal-app/core getDefaultLevelName / getLevelDisplayName ("Ground Floor" / "Floor N" / "Basement N") lived in packages/editor's internal lib, so viewer-only surfaces couldn't reach them and fell back to hand-rolled "Level N" labels. The helpers are pure domain logic, so they move to core and export from its barrel; the editor package's seven call sites now import them from there. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Fable 5 <noreply@anthropic.com>