please add a dark mode

### Describe the new feature or improvement you would like to see in the Envoy mobile app.

i'd greatly appreciate, if you would be able to add a dark mode to envoy.

### Explain the specific use case or scenario where this feature would be valuable to users.

_No response_

### Ideas for implementation

_No response_

### Screenshots/Design

_No response_

### Additional Context

_No response_