Merge PR #35: fix batch of reported issues (#18, #19, #23, #25, #26, #27, #28)

Regenerated ANTLR parser from merged grammar to resolve conflicts
in auto-generated files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

mdl/ast/ast_expression.go

@@ -108,6 +108,16 @@ type QualifiedNameExpr struct {
 
 func (e *QualifiedNameExpr) isExpression() {}
 
+// IfThenElseExpr represents an inline if-then-else expression:
+// if condition then trueExpr else falseExpr
+type IfThenElseExpr struct {
+	Condition Expression // Condition expression
+	ThenExpr  Expression // Expression when condition is true
+	ElseExpr  Expression // Expression when condition is false
+}
+
+func (e *IfThenElseExpr) isExpression() {}
+
 // ============================================================================
 // XPath-Specific Expression Types
 // ============================================================================

mdl/catalog/builder_microflows.go

@@ -318,6 +318,8 @@ func getDataTypeName(dt microflows.DataType) string {
 		return "String"
 	case *microflows.DateTimeType:
 		return "DateTime"
+	case *microflows.DateType:
+		return "Date"
 	case *microflows.ObjectType:
 		return "Object:" + t.EntityQualifiedName
 	case *microflows.ListType: