fix: hide Stop button once response streaming begins

When a prompt is running, the Stop button was shown throughout the entire
process (thought chain + response streaming). Now the Stop button is only
shown during the thought chain phase. Once the response starts streaming,
the Send button is displayed instead.

Changes:
- Add isResponseStreaming computed state in ExistingChat.jsx
- Thread isResponseStreaming prop through InputPrompt, PromptInput
- Update button condition in MonacoPromptInput and DefaultPromptInput

🤖 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

@@ -6,6 +6,7 @@ import { Sender } from "@ant-design/x";
 function DefaultPromptInput({
   value,
   isPromptRunning,
+  isResponseStreaming,
   onSenderChange,
   onSubmit,
   onCancel,
@@ -25,7 +26,7 @@ function DefaultPromptInput({
       actions={(_, info) => {
         const { SendButton, LoadingButton } = info.components;
 
-        if (isPromptRunning) {
+        if (isPromptRunning && !isResponseStreaming) {
           return (
             <Tooltip title="Stop">
               <LoadingButton variant="text" color="secondary" shape="default" />
@@ -64,6 +65,7 @@ function DefaultPromptInput({
 DefaultPromptInput.propTypes = {
   value: PropTypes.string.isRequired,
   isPromptRunning: PropTypes.bool.isRequired,
+  isResponseStreaming: PropTypes.bool,
   onSenderChange: PropTypes.func.isRequired,
   onSubmit: PropTypes.func.isRequired,
   onCancel: PropTypes.func.isRequired,

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

@@ -246,6 +246,13 @@ const ExistingChat = memo(function ExistingChat({
     return -1;
   }, [chatMessages, chatIntents]);
 
+  // Check if response is actively streaming (thought chain done, response started)
+  const isResponseStreaming = useMemo(() => {
+    if (!chatMessages?.length) return false;
+    const lastMessage = chatMessages?.[chatMessages.length - 1];
+    return isPromptRunning && lastMessage?.response?.length > 0;
+  }, [chatMessages, isPromptRunning]);
+
   useEffect(() => {
     if (chatMessages.length) {
       setLastChatMessageId(
@@ -454,6 +461,7 @@ const ExistingChat = memo(function ExistingChat({
         <InputPrompt
           savePrompt={handleSavePrompt}
           isPromptRunning={isPromptRunning}
+          isResponseStreaming={isResponseStreaming}
           chatIntents={chatIntents}
           selectedChatIntent={selectedChatIntent}
           setSelectedChatIntent={setSelectedChatIntent}

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

@@ -10,6 +10,7 @@ const InputPrompt = memo(function InputPrompt({
   savePrompt,
   isNewChat = false,
   isPromptRunning,
+  isResponseStreaming = false,
   chatIntents,
   selectedChatIntent,
   setSelectedChatIntent,
@@ -209,6 +210,7 @@ const InputPrompt = memo(function InputPrompt({
           value={value}
           editorHeight={editorHeight}
           isPromptRunning={isPromptRunning}
+          isResponseStreaming={isResponseStreaming}
           onSenderChange={handleSenderChange}
           onSubmit={handleSubmit}
           onEditorMount={handleEditorMount}
@@ -252,6 +254,7 @@ InputPrompt.propTypes = {
   savePrompt: PropTypes.func.isRequired,
   isNewChat: PropTypes.bool,
   isPromptRunning: PropTypes.bool.isRequired,
+  isResponseStreaming: PropTypes.bool,
   chatIntents: PropTypes.array.isRequired,
   selectedChatIntent: PropTypes.string,
   setSelectedChatIntent: PropTypes.func.isRequired,

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

@@ -12,6 +12,7 @@ const MonacoPromptInput = memo(function MonacoPromptInput({
   value,
   editorHeight,
   isPromptRunning,
+  isResponseStreaming,
   onEditorMount,
   onMonacoChange,
   onSubmit,
@@ -159,9 +160,8 @@ const MonacoPromptInput = memo(function MonacoPromptInput({
   return (
     <div className="monaco-editor-wrapper">
       {editorContent}
-
       <div className="monaco-editor-send">
-        {isPromptRunning ? (
+        {isPromptRunning && !isResponseStreaming ? (
           <Tooltip title="Stop">
             <Button type="text" icon={<CloseOutlined />} onClick={onCancel} />
           </Tooltip>
@@ -204,6 +204,7 @@ MonacoPromptInput.propTypes = {
   value: PropTypes.string.isRequired,
   editorHeight: PropTypes.number.isRequired,
   isPromptRunning: PropTypes.bool.isRequired,
+  isResponseStreaming: PropTypes.bool,
   onEditorMount: PropTypes.func,
   onMonacoChange: PropTypes.func.isRequired,
   onSubmit: PropTypes.func.isRequired,

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

@@ -10,6 +10,7 @@ const PromptInput = memo(function PromptInput({
   value,
   editorHeight,
   isPromptRunning,
+  isResponseStreaming,
   onSenderChange,
   onSubmit,
   onEditorMount,
@@ -34,6 +35,7 @@ const PromptInput = memo(function PromptInput({
       <DefaultPromptInput
         value={value}
         isPromptRunning={isPromptRunning}
+        isResponseStreaming={isResponseStreaming}
         onSenderChange={onSenderChange}
         onSubmit={onSubmit}
         onCancel={onCancel}
@@ -49,6 +51,7 @@ const PromptInput = memo(function PromptInput({
       value={value}
       editorHeight={editorHeight}
       isPromptRunning={isPromptRunning}
+      isResponseStreaming={isResponseStreaming}
       onEditorMount={onEditorMount}
       onMonacoChange={onMonacoChange}
       onSubmit={onSubmit}
@@ -70,6 +73,7 @@ PromptInput.propTypes = {
   value: PropTypes.string.isRequired,
   editorHeight: PropTypes.number.isRequired,
   isPromptRunning: PropTypes.bool.isRequired,
+  isResponseStreaming: PropTypes.bool,
   onSenderChange: PropTypes.func.isRequired,
   onSubmit: PropTypes.func.isRequired,
   onEditorMount: PropTypes.func.isRequired,