Bug: No SSE stream connection when resuming a conversation

[nikitax75]

Description

When resuming an existing conversation (clicking on a conversation from History and sending a follow-up message), the frontend does not establish a Server-Sent Events (SSE) connection to the stream URL returned by the API.

Steps to Reproduce

1. Start cui-server and create a new conversation
2. After the conversation completes, go to History tab
3. Click on the conversation to open it
4. Send a follow-up message

Expected Behavior

• The frontend should connect to /api/stream/{streamingId} to receive real-time updates
• The new message and response should appear in the UI without needing to refresh

Actual Behavior

• The API call POST /api/conversations/start with resumedSessionId succeeds
• The server returns a valid streamUrl
• The frontend does NOT connect to the stream URL
• The UI does not update to show the new messages
• Refreshing the page shows the messages were saved correctly

Technical Details

API Response (correct):

{
  "streamingId": "xxx",
  "streamUrl": "/api/stream/xxx",
  "sessionId": "original-session-id",
  "cwd": "/app",
  "tools": [...]
}

Network activity comparison:

• New conversation: Makes request to /api/stream/{id} ✅
• Resumed conversation: No stream request made ❌

Environment

• cui-server version: 0.6.3
• Node.js: 20.x
• Browser: Chromium (tested via Playwright)

Workaround

Refreshing the page after sending a follow-up message shows the response correctly.