WEB-824: Fix null handling in PrettyPrintPipe (#3339)

Guard against null/undefined/non-string values; return empty string to
prevent runtime crash and objects/numbers reaching [innerHTML] consumer.

Made-with: Cursor

Author: tkshsbcue

src/app/pipes/pretty-print.pipe.ts

@@ -12,6 +12,9 @@ import * as vkbeautify from 'vkbeautify';
 @Pipe({ name: 'prettyPrint' })
 export class PrettyPrintPipe implements PipeTransform {
   transform(value: any) {
+    if (value == null || typeof value !== 'string') {
+      return '';
+    }
     if (value.charAt(0) === '{' && value.charAt(value.length - 1) === '}') {
       try {
         return vkbeautify.json(value);