website refactor

docs/architecture/core/DOMAIN_OBJECTS.md

@@ -93,9 +93,19 @@ Value Objects MUST NOT:
 	•	contain business workflows
 	•	reference entities
 	•	perform IO
+	•	**contain presentation or formatting logic** (e.g., `formatForDisplay()`)
 
 ⸻
 
+### Domain vs. Presentation Value Objects
+
+It is critical to distinguish between **Domain Value Objects** and **Presentation Value Objects** (Displays):
+
+- **Domain Value Objects (Core):** Protect business meaning and invariants. They are pure and know nothing about how data is shown to users.
+- **Display Objects (Website):** Protect presentation logic and formatting. They are used by the Website (both server and client) to ensure consistent display.
+
+If the API needs to return formatted strings, this logic belongs in **API Presenters**, not in Domain Value Objects.
+
 Creation Rules
 	•	create() for new domain meaning
 	•	fromX() for interpreting external formats