feat(furniture): nightstand legs, bookcase columns/drawers, AC unit LG style, soundbars, wood-cube sconce

- NIGHTSTAND: optional legs with adjustable height (capped at 60% of total height)
- BOOKCASE: shelfColumns with vertical dividers, per-cell drawer fronts with handles,
  z-fighting fix between dividers and back panel, stale drawerCells pruned on grid shrink
- AC_UNIT: new 'lg' style with dark vent, grille lines, deflector flap, LG accent
- SPEAKER: new 'soundbar' variant (90/110/140cm) with grille, driver cones, LED strip;
  SpeakerMesh split into dispatcher + SpeakerCabinetMesh to keep hook order stable
- Wall light: new 'wood-cube' style (wooden block sconce with top/bottom glow)
- PropertiesPanel: tf() helper replaces repeated i18n.exists fallbacks; inline checkbox
  styles consolidated into styles.checkboxLabel
- Translations: en/ru entries for new property keys

packages/shared/src/index.ts

@@ -42,6 +42,7 @@ export type {
   PositionAnchor,
   ElectricalType,
   OutletDirection,
+  AcUnitStyle,
   WallLightStyle,
   FurnitureTexture,
   ElectricalItem,
@@ -66,6 +67,7 @@ export {
   DOOR_OPEN_DIRECTIONS,
   ELECTRICAL_TYPES,
   OUTLET_DIRECTIONS,
+  AC_UNIT_STYLES,
   WALL_LIGHT_STYLES,
   FURNITURE_TEXTURES,
   TEXTURABLE_FURNITURE,

packages/shared/src/types/elements.ts

@@ -228,11 +228,15 @@ export type ElectricalType = (typeof ELECTRICAL_TYPES)[number];
 export const OUTLET_DIRECTIONS = ['horizontal', 'vertical'] as const;
 export type OutletDirection = (typeof OUTLET_DIRECTIONS)[number];
 
+export const AC_UNIT_STYLES = ['generic', 'lg'] as const;
+export type AcUnitStyle = (typeof AC_UNIT_STYLES)[number];
+
 export const WALL_LIGHT_STYLES = [
   'classic',
   'pendant-globe',
   'sconce-up',
   'sconce-down',
+  'wood-cube',
 ] as const;
 export type WallLightStyle = (typeof WALL_LIGHT_STYLES)[number];