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>

ksuid_binary.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/go-jet/jet/v2/mysql"
 	"github.com/segmentio/ksuid"
 )
 
@@ -44,19 +43,16 @@ func ParseBinaryKSUID(b []byte) (BinaryKSUID, error) {
 	return BinaryKSUID{KSUID: id}, nil
 }
 
-// BinExpr returns a Jet string expression for binary-encoded IN clauses.
-func (b BinaryKSUID) BinExpr() mysql.StringExpression {
-	if b.IsNil() {
-		return mysql.StringExp(mysql.NULL)
-	}
-	return mysql.String(string(b.Bytes()))
-}
-
 // AsStringKSUID returns a StringKSUID view of the same identifier.
 func (b BinaryKSUID) AsStringKSUID() StringKSUID {
 	return StringKSUID{KSUID: b.KSUID}
 }
 
+// Expr returns a Jet expression for this BinaryKSUID. See [BinaryKSUIDExpr].
+func (b BinaryKSUID) Expr() Expression {
+	return BinaryKSUIDExpr(b)
+}
+
 // Scan implements sql.Scanner for binary-backed KSUID columns.
 func (b *BinaryKSUID) Scan(src any) error {
 	switch v := src.(type) {