Domain Boundary Diagrams — [DomainBoundary("Layer")] on a class or method triggers four new constants: _LayerView (architecture flowchart TD), _Stats (Markdown table), _ErrorSurface (fail-edges only), _ErrorPropagation (errors grouped by layer)
[DomainBoundary] on classes — attribute now valid on classes; all methods inherit the layer; method-level annotation takes priority
Automatic layer detection — LayerDetector resolves layer from [DomainBoundary] annotation or namespace heuristics (*.Domain.*, *.Application.*, *.Infrastructure.*, *.Controllers.*)
Layer subgraph coloring — _LayerView and _ErrorPropagation color outer layer subgraph containers via Mermaid class directive