fix(mcp): distinguish roof support levels from stories

packages/mcp/src/prompts/scene-guidance.ts

@@ -7,6 +7,7 @@ export const SCENE_DESIGN_GUIDANCE = [
   '  - For clear concrete requests, act with reasonable defaults instead of asking for clarification.',
   '  - For full homes/apartments, include realistic support spaces: kitchen, living/dining, bathrooms, hallway/entry, storage/laundry where appropriate.',
   '  - For multi-story buildings, create separate level-owned story shells. Do not stretch first-floor exterior walls to cover upper floors.',
+  '  - Treat requested story count as occupied stories, not raw level count; dedicated roof/support levels are allowed and must not be deleted just to match a story count.',
   '',
   'Preferred phased tool workflow:',
   '  - Query first with list_levels, get_level_summary, get_walls, or get_zones when editing an existing scene.',
@@ -14,6 +15,7 @@ export const SCENE_DESIGN_GUIDANCE = [
   '  - For rooms, prefer create_room, then add_door/add_window, then furnish_room.',
   '  - For stairs between floors, prefer create_stair_between_levels so slab/ceiling openings stay rectangular and do not duplicate auto-generated holes.',
   '  - For roofs, prefer create_roof and let it create/use a dedicated roof level above the top occupied story so solo/exploded level views can isolate the roof.',
+  '  - verify_scene reports both levelCount and occupiedStoryCount. Use occupiedStoryCount when checking whether a one-story/two-story brief was satisfied.',
   '  - add_door/add_window use t = 0..1 along a wall: 0 is start, 0.5 is center, 1 is end.',
   '  - Use search_assets before place_item when placing a specific catalog item.',
   '  - Use apply_patch for precise bulk edits that the semantic tools cannot express.',