[Optimization] Move `Dashboard.py` to the last stack (and thus, `us-east-1`)

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

It's impossible to log anything in `start_system_stack.py`, since it's initialized in the app after the dashboard is. Originally I wanted the dashboard where the user will be the most, so I put it as late as possible in `container_manager_stack.py`.

I'm thinking it'll be a lot better to have it at the very end of the application (so `start_system_stack.py`, mayybe a nested stack in it?).

I DON'T want another stack, so having a new stack with just a dashboard at the end isn't the way to go.

### Describe the solution you'd like

^^^

### Describe alternatives you've considered

^^^

### Acknowledgements

- [x] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

Start by reading Dashboard.py, start_system_stack.py, and container_manager_stack.py to trace how the CDK stacks are constructed and ordered; synthesize the application to inspect the resulting stack placement and region. Done means Dashboard.py is handled by the final application stack in us-east-1, logging in start_system_stack.py is possible, and no standalone dashboard-only stack is introduced.

Written by the indexing model from the issue text.