Stage 2 Geometry Consolidation

Verifies Atlas geometry delegates to the production authority with zero duplicated constants

Post-Stage-2 Architecture

Atlas Document Model
       ↓
atlasTemplateGeometry.js (FACADE — no calculations)
       ↓ delegates to
┌──────────────────────────────────────────────────┐
│  PRODUCTION GEOMETRY AUTHORITY                     │
│  src/lib/templateGeometry.js                      │
│  • getCanvasGeometry(templateId)                   │
│  • getFullLayout(templateId)                       │
│  • isLandscapeTemplate(templateId)                │
│  • getFlowBands(templateId)                        │
│  SINGLE SOURCE OF TRUTH for all geometry           │
└──────────────────────────────────────────────────┘
       ↓ consumed by
       AtlasProductionAdapter (sole integration point)
       ↓
       LetterRenderSurface (protected — unchanged)