chore: merge

src/pages/tools/string/rot13/service.ts

@@ -0,0 +1,7 @@
+export function rot13(input: string): string {
+  return input.replace(/[a-zA-Z]/g, (char) => {
+    const charCode = char.charCodeAt(0);
+    const baseCode = charCode >= 97 ? 97 : 65; // 'a' or 'A'
+    return String.fromCharCode(((charCode - baseCode + 13) % 26) + baseCode);
+  });
+}