Fix furniture scale — halve FBX model sizes to fit rooms (#15)

Hospital FBX models are authored in centimetres (a bed is ~200 cm
long). The previous uniform scale of 0.012 made a bed occupy ~2.4
tiles — much too large. New per-type scale factors:

  bed:              0.006  (~1.2 tiles long)
  chair:            0.008  (~0.5 tiles)
  waiting_chair:    0.007  (~0.5 tiles)
  computer:         0.008  (~0.4 tiles)
  diagnostic_table: 0.006  (~1.2 tiles)
  medical_equipment:0.007  (~0.5 tiles)
  wheelchair:       0.007  (~0.5 tiles)

Furniture now fits proportionally within room boundaries.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: stedrew

environment/react_frontend/src/components/ThreeFloorPlan.tsx

@@ -68,17 +68,19 @@ const MODEL_URLS: Record<string, string> = {
 const TEXTURE_ATLAS_URL = '/models/hospital/Texture_Atlas_Colors_2.png';
 
 /**
- * Scale factors per equipment type. Hospital FBX models have varied
- * native sizes; these factors normalise them to roughly 1 tile.
+ * Scale factors per equipment type. Hospital FBX models are authored
+ * in centimetres; these factors convert to Three.js units where 1
+ * unit = 1 map tile (~3 ft / ~1 m). A hospital bed is ~200 cm long
+ * in the FBX, and should occupy ~1.2 tiles on screen → scale ≈ 0.006.
  */
 const MODEL_SCALE: Record<string, number> = {
-  bed: 0.012,
-  chair: 0.012,
-  waiting_room_chair: 0.012,
-  computer: 0.012,
-  diagnostic_table: 0.012,
-  medical_equipment: 0.012,
-  wheelchair: 0.012
+  bed: 0.006,
+  chair: 0.008,
+  waiting_room_chair: 0.007,
+  computer: 0.008,
+  diagnostic_table: 0.006,
+  medical_equipment: 0.007,
+  wheelchair: 0.007
 };
 
 /* ZONE_COLORS and CANVAS_BACKGROUND_COLOR imported from @/theme/colors */