chore: add Nextcloud 36 support and create stable35 branch

[vitormattos]

Description

Prepare Profile fields for Nextcloud 36 while preserving the Nextcloud 35 maintenance line.

Tasks

• Create the stable35 branch from the current main branch before changing the Nextcloud maximum version.
• Keep stable35 compatible with Nextcloud 35 (max-version="35").
• In main, update appinfo/info.xml from:

<nextcloud min-version="32" max-version="35"/>

to:

<nextcloud min-version="32" max-version="36"/>

• Verify CI and tests against the supported Nextcloud versions.

Acceptance criteria

• stable35 exists and remains the maintenance branch for Nextcloud 35.
• main declares Nextcloud 36 as the maximum supported version.
• Existing CI checks pass after the compatibility update.

Creating stable35 is an internal maintainer task and should be done by the LibreCode team.