Add Account Button & Ability to Switch Between Nextcloud Accounts (Web Version)

Currently, there is no straightforward way to switch between multiple Nextcloud accounts within the web interface. This feature request proposes adding an "Account Button" to the Nextcloud web version, which will allow users to easily switch between their Nextcloud accounts without needing to log out and log back in.

Use Case:

Many users manage multiple Nextcloud instances (e.g., personal and work accounts) and would benefit from the ability to seamlessly switch between them without interrupting their workflow. This feature would increase productivity and provide a smoother user experience for those with multiple accounts.

Proposed Solution:

1. Add a user-friendly Account Button in the web interface (e.g., in the top right corner).
2. Clicking the Account Button would show a dropdown or modal listing the user's Nextcloud accounts.
3. Users would be able to select an account from the list, and the interface would automatically switch to that account.
4. Optionally, include the ability to add/remove accounts directly from the dropdown or modal interface.
5. The switch should preserve session data where possible (e.g., avoiding the need to re-enter credentials for linked accounts).

Benefits:

• Enhanced User Experience: Users can switch accounts with just a click, making it easier to manage personal and work accounts.
• Increased Productivity: No more logging out and back in, which saves time.
• Convenience: Smooth account management within the Nextcloud web interface.

Additional Context:

• This feature is particularly useful for users who work with multiple Nextcloud instances, whether for personal, work, or collaborative purposes.
• It's also beneficial for Nextcloud admins managing several organizations or domains who need quick access to various accounts.

The issue names no files, tests, or entry points. Start by identifying the web interface and authentication/session areas involved, then clarify the account model, security requirements, and expected behavior before implementation; done should include an agreed account-switching design and validation of the complete user flow.