Screenshare in EC within ED selects the wrong window to share(!)

### Steps to reproduce

1. Start an EC call within ED (macOS)
2. Start a screenshare
3. You get a choice between "share entire screen" and "share window"
4. No matter what you select on, it appears to share ED itself (which can be pretty embarrassing if you weren't expecting to suddenly share your Element with the people on the call...)
5. You also don't seem to get a choice to select which window to share.

### Outcome

#### What did you expect?

Screenshare choice not to be ignored.

#### What happened instead?

It always tries to screenshare ED itself, no matter what you ask for.

This is a borderline security issue, given risk of accidentally leaking data.

### Operating system

macOS Sequoia

### Application version

v1.12.6

### How did you install the app?

_No response_

### Homeserver

_No response_

### Will you send logs?

No

Reproduce the issue using an EC call within ED on macOS Sequoia, following the listed screenshare steps. Start by tracing the Element Call and Element Desktop screenshare entry points; done means the chooser respects both "share entire screen" and "share window" selections and allows the intended window to be selected.

Written by the indexing model from the issue text.