Pinned Chats section doesn't exist after pinning first chat in Agents window until reload

### Repro steps

1. Open the **Agents** window.
2. Go to **Chats** (first time usage; no existing chats/pinned items).
3. Create a chat, send a message
3. In the sidebar, click **Pin** on a chat.

### Expected

The chat should appear under a visible **Pinned** section in the sidebar.

### Actual

The chat/sidebar section disappears:
- **No chats** are shown
- **No pinned section** is shown

The pinned section only reappears after closing and reloading the window.

### Notes

- This was observed on first-time use of Chats in the Agents window.
- Reloading the window restores the pinned section.