Improve actual frontend performance

[ChristophWurst]

Is your feature request related to a problem? Please describe.

As a Nextcloud Mail user some operations feel slow.

Describe the solution you'd like

Make the frontend operate faster

Describe alternatives you've considered

N/a

Additional context

No response

[cenobitz]

https://github.com/user-attachments/assets/fc11a502-486a-4cc9-b3dc-7fe8fa41355b

Here is a model instance of Nextcloud, which is supposed to encourage potential customers to implement it. It takes 10-15 seconds to open a tab. I think it's good that they didn't enable the MAIL APP function in the test instance (without which work in such a solution is pointless), because opening an email on a very good server takes 4-6 seconds, which is a disaster.

an interesting form of advertising the product.

[st3iny]

Done