refactor(ksuid): replace BinExpr with top-level expr helpers

Adds StringKSUIDExpr and BinaryKSUIDExpr for use with ExprValues, plus
Expr() methods on both types. Removes ExprStringKSUIDs and BinExpr.

Co-authored-by: Cursor <cursoragent@cursor.com>

jet_expr.go

@@ -25,11 +25,18 @@ func ExprStringers(values []fmt.Stringer) []Expression {
 	return expressions
 }
 
-// ExprStringKSUIDs converts StringKSUID pointers to Jet string expressions.
-func ExprStringKSUIDs(ids []*StringKSUID) []Expression {
-	expressions := make([]Expression, len(ids))
-	for i, id := range ids {
-		expressions[i] = mysql.String(id.String())
+// StringKSUIDExpr returns a Jet expression for a string-encoded KSUID column.
+func StringKSUIDExpr(id StringKSUID) Expression {
+	if id.IsNil() {
+		return mysql.StringExp(mysql.NULL)
 	}
-	return expressions
+	return mysql.String(id.String())
+}
+
+// BinaryKSUIDExpr returns a Jet expression for a binary-encoded KSUID column.
+func BinaryKSUIDExpr(id BinaryKSUID) Expression {
+	if id.IsNil() {
+		return mysql.StringExp(mysql.NULL)
+	}
+	return mysql.String(string(id.Bytes()))
 }