[Bug] Sidebar context menu "Fork" creates two forked chats instead of one (Desktop)

<img width="778" height="400" alt="Image" src="https://github.com/user-attachments/assets/b8404a62-c4da-44ce-bd8d-fec7b1344f27" />
<img width="664" height="358" alt="Image" src="https://github.com/user-attachments/assets/511f2f90-bf0a-4b62-bbac-48364283b0b3" />
<img width="665" height="270" alt="Image" src="https://github.com/user-attachments/assets/fdf111d9-fc85-44cd-8864-a4970ddc308c" />

Summary

In Claude Code Desktop, right-clicking a chat in the left sidebar and selecting Fork from the context menu creates two new forked chats instead of one.

Expected behavior

Right-click → Fork should create exactly one new forked chat, leaving the original untouched. After the action, the sidebar should show: original + 1 new fork = +1 chat total.

Actual behavior

After right-click → Fork, the sidebar shows: original + 2 new forks. Each invocation of the context menu Fork item creates two duplicate forked sessions per single click.

Steps to reproduce

1. Open Claude Code Desktop with at least one existing chat in the sidebar.
2. Right-click any chat in the left sidebar.
3. Click Fork in the context menu.
4. Observe: two new forked chats appear in the sidebar instead of one.

Environment

• OS: Windows 11 Pro, 10.0.26200
• Platform: win32
• Claude Code version: 2.1.131
• Surface: Desktop app, sidebar right-click context menu

Possible cause

Likely a double-trigger of the fork action in the GUI handler — the context menu item appears to invoke the fork operation twice per click.

Workaround

Typing /fork or /branch directly into the chat input (inside the chat itself) creates exactly one forked chat as expected. The bug only occurs through the sidebar context menu path.