Add strict custom field registry

toolkit/internal/gsp/init.go

@@ -66,6 +66,8 @@ entry:
   - %s
 scan:
   - design
+customFieldPolicy: strict
+fieldRegistry: gsp.fields
 stageRules:
   design:
     minResolution: L0
@@ -94,10 +96,16 @@ type: concept
 resolution: L0
 context: Project entry GSP.
 `, yamlScalar(entry))
+	fieldsContent := `gspFieldsVersion: 0.1
+fields: {}
+`
 
 	if err := writeInitFile(absRoot, filepath.Join(absRoot, "gsp.manifest"), []byte(manifest), options.Force, &result); err != nil {
 		return InitResult{}, err
 	}
+	if err := writeInitFile(absRoot, filepath.Join(absRoot, "gsp.fields"), []byte(fieldsContent), options.Force, &result); err != nil {
+		return InitResult{}, err
+	}
 	if err := writeInitFile(absRoot, entryFile, []byte(entryContent), options.Force, &result); err != nil {
 		return InitResult{}, err
 	}