add minor fixes to JS/TS Exercise

[davbizer93]

Went through the JS/TS Exercise E2E and have 1-2 suggestions. Below are my notes

• Cloud Sdk for AI TS - [03](https://github.com/SAP-samples/codejam-code-based-agents/blob/main/exercises/JavaScript/03-add-your-first-tool.md) has an error : ```export class RPT1Client {
  private client: RptClient;

  constructor() {
  this.client = new RptClient({ resourceGroup: process.env.RESOURCE_GROUP! });
  }

  async predictWithoutSchema(payload: RPT1Payload): Promise {
  const prediction = await this.client.predictWithoutSchema(payload as any);
  return prediction;
  }
  }```

--> no deployment found when passing resource group
--> Should be like in solution with model name :

constructor(modelName: 'sap-rpt-1-small' | 'sap-rpt-1-large' = 'sap-rpt-1-small') {

// Initialize the SDK client

// By default, it uses 'sap-rpt-1-small'

this.client = new RptClient(modelName)

}

--> Update Step 2 (currently not working)
--> Update Step 3 to include payload in buildGraph():

const workflow = new StateGraph<AgentState>({

channels: {

payload: null,

suspect_names: null,

appraisal_result: null,

messages: null,

},

});