removed formatter for rules

validation-core/docs/validation_architecture.md

@@ -282,17 +282,6 @@ mask:
 Canvas uses this for display/editing. Backend expects raw values without mask
 literals.
 
-### Formatter
-
-```text
-formatter:
-  type: "PhoneFormatter"
-  options: []
-  description: optional
-```
-
-Formatter is resolved client-side. Backend stores it but does not execute it.
-
 ### External Validation
 
 ```text
@@ -331,7 +320,6 @@ limits section
 pattern section
 allowed values section
 mask section
-formatter section
 external validation toggle
 ```