feat: customizable multi-layout for /app route

[bryanlundberg]

The objective is to enable customization of the /app route by introducing a flexible layout system. This would allow users to adjust the interface to better match their preferences, similar to the experience offered by other popular timer applications.

Some users particularly those who stream require alternative layout distributions to better suit their setup and audience. The current layout does not fully accommodate these needs.

The statistics and cube visualization section should be redesigned to be more elegant, visually balanced, and adaptable to different layouts. This would improve usability and make the interface more suitable for both regular use and streaming scenarios.