Support WITH TOTALS at end of SELECT statement

WITH TOTALS can appear after GROUP BY or at the end of SELECT
even without GROUP BY. Added parsing support after LIMIT clause.

Test count: 5550 -> 5554 (+4 tests)

Author: claude

parser/parser.go

@@ -354,6 +354,13 @@ func (p *Parser) parseSelect() *ast.SelectQuery {
 		}
 	}
 
+	// Parse WITH TOTALS (can appear after GROUP BY or at end of SELECT)
+	if p.currentIs(token.WITH) && p.peekIs(token.TOTALS) {
+		p.nextToken()
+		p.nextToken()
+		sel.WithTotals = true
+	}
+
 	// Parse SETTINGS clause
 	if p.currentIs(token.SETTINGS) {
 		p.nextToken()