fix: handle negative indentation levels in getIndent method

Author: NaccOll

src/core/task/tool-call-helper.ts

@@ -223,7 +223,10 @@ export class StreamingToolCallProcessor {
 	 * @returns A string of tabs.
 	 */
 	private getIndent(level: number): string {
-		return "\t".repeat(level)
+		if (level >= 0) {
+			return "\t".repeat(level)
+		}
+		return ""
 	}
 
 	/**