[Nextcloud 31] Text does not work on public shares

[susnux]

Describe the bug

With Nextcloud 31 public shares also use the same UI as the files app, meaning the legacy UI is dropped in favor of the new (Nextcloud 28) Vue UI.
Sadly the text app does not work out-of-the-box, meaning if you open a public share and then open a markdown file (any file that text can open) the app fails to show the file.
The problem seems that Text does not detect the public share correctly and thus calls the wrong entry point to create a session.

Maybe you can use this functions for public share detection / share token retrieval if needed:
https://nextcloud-libraries.github.io/nextcloud-sharing/modules/public.html

To Reproduce
Steps to reproduce the behavior:

1. Use the master branch (Nextcloud 31)
2. Create a public share
3. Put a MD file inside
4. Open public share
5. Try to view the markdown file

Expected behavior
Text can open and view / edit the file as with Nextcloud 30 and before.

Screenshots

Bildschirmaufnahme_20240906_164408.webm

XHRPUT
http://localhost:8081/index.php/apps/text/session/251/create
[HTTP/1.1 401 Unauthorized 28ms]

	
fileId	251
filePath	"/Neue Textdatei.md"
forceRecreate	false
guestName	""
token	null

Server details:

• Nextcloud version: 31
• PHP Version: 8.3

[susnux]

Thank you @mejo- for awesomely fast fixing this 🚀