updated regex sanitization

-allows %
-updated escape characters to \

src/Terminal/commands/expr.ts

@@ -17,7 +17,7 @@ export function expr(
   const expr = args.join("");
 
   // Sanitize the math expression
-  const sanitizedExpr = expr.replace(/s+/g, "").replace(/[^-()\d/*+.]/g, "");
+  const sanitizedExpr = expr.replace(/s+/g, "").replace(/[^-()\d\*+.\%]/g, "");
   let result;
   try {
     result = eval(sanitizedExpr);