shape shows off the document area when you click and drag the anchor

[printfdebugging]

Describe the Bug

Steps to Reproduce

1. insert a shape
2. click on the anchor on the left of it
3. drag down and notice the shadow of the shape in the bottom left area of the window

Expected Behavior

the shape's shadow should show up over the shape, not on the side area of the document.

Desktop

(Please complete the following information)

• OS: Arch Linux
• Browser: Brave Browser 139.1.81.137
• Version:
  COOLWSD version: 25.04.5.1(git hash: b911526)
  LOKit version: Collabora OfficeDev 25.04.5.1(git hash: 1bfca87e59)
  Served by: Arch Linux
  Server ID: 87e5047b
  WOPI host:

Additional Context

#3461
Add any other context about the problem here.