POST-merge bug — /api/v1/analytics/object/{id}/quartirography returned 500
because SQL referenced f.type, but domrf_kn_flats has flat_type column.
Verified via DB: query now returns 4 buckets (Нежилые/1-3-комн.) for obj=65136.
Affected endpoint: GET /api/v1/analytics/object/{obj_id}/quartirography