fix(chat): When user reject executing command, it should not send messages to LLM (aws#7052)

## Problem
Right now, when user reject executing command, chat would send the
reject message to LLM and LLM would response. The loop would still
continue
<img width="428" alt="Screenshot 2025-04-15 at 11 36 15 AM"
src="https://github.com/user-attachments/assets/cd5d1c03-271a-416e-9c9e-d62068a82020"
/>
## Solution
<img width="428" alt="Screenshot 2025-04-15 at 11 44 57 AM"
src="https://github.com/user-attachments/assets/66a6a05a-444d-4e90-bce1-c1bfb2ffa217"
/>




---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

---------

Co-authored-by: chungjac <[email protected]>

Author: Randall-Jiang

packages/core/src/codewhispererChat/controllers/chat/controller.ts

@@ -894,6 +894,8 @@ export class ChatController {
                 currentToolUse.name === ToolType.ListDirectory)
         ) {
             session.toolUseWithError.error = new Error('Tool use was rejected by the user.')
+            session.setToolUseWithError(undefined)
+            this.messenger.sendAsyncEventProgress(message.tabID!, false, undefined)
         } else {
             getLogger().error(
                 `toolUse name: ${currentToolUse!.name} of toolUseWithError in the stored session doesn't match when click shell command reject button.`
@@ -928,13 +930,24 @@ export class ChatController {
             case 'reject-shell-command':
             case 'reject-tool-use':
                 await this.rejectShellCommand(message)
-                await this.processToolUseMessage(message)
+                if (message.tabID) {
+                    await this.sendCommandRejectMessage(message.tabID)
+                }
+                if (message.triggerId) {
+                    ConversationTracker.getInstance().markTriggerCompleted(message.triggerId)
+                }
                 break
             default:
                 getLogger().warn(`Unhandled action: ${message.action.id}`)
         }
     }
 
+    private async sendCommandRejectMessage(tabID: string) {
+        const session = this.sessionStorage.getSession(tabID)
+        session.setAgenticLoopInProgress(false)
+        this.messenger.sendDirectiveMessage(tabID, '', 'Command Rejected')
+    }
+
     private async restoreBackup(message: CustomFormActionMessage) {
         const tabID = message.tabID
         const toolUseId = message.action.formItemValues?.toolUseId