fix: address code review feedback

- Add explicit default `= false` for isResponseStreaming in MonacoPromptInput and DefaultPromptInput
- Disable SendButton when isPromptRunning to prevent concurrent prompt submission

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: tahierhussain

frontend/src/ide/chat-ai/DefaultPromptInput.jsx

@@ -6,7 +6,7 @@ import { Sender } from "@ant-design/x";
 function DefaultPromptInput({
   value,
   isPromptRunning,
-  isResponseStreaming,
+  isResponseStreaming = false,
   onSenderChange,
   onSubmit,
   onCancel,
@@ -52,7 +52,7 @@ function DefaultPromptInput({
                 />
               }
               shape="default"
-              disabled={!value}
+              disabled={!value || isPromptRunning}
               className={shouldHighlightSend ? "onboarding-send-highlight" : ""}
             />
           </Tooltip>

frontend/src/ide/chat-ai/MonacoPromptInput.jsx

@@ -12,7 +12,7 @@ const MonacoPromptInput = memo(function MonacoPromptInput({
   value,
   editorHeight,
   isPromptRunning,
-  isResponseStreaming,
+  isResponseStreaming = false,
   onEditorMount,
   onMonacoChange,
   onSubmit,