feat: Add Feature Flags with Upstash

[mosesintech]

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

When the project is live in production and new features continue to be developed, it would be good to use feature flags to slowly roll them out to debug production errors.

Describe the solution you'd like to see

Upstash has a generous free tier for a Redis database, and their Edge Flags feature is free to use. Using their @upstash/edge-flags will allow us to develop using feature flags.

Describe alternate solutions

Will explore in the future.

Additional information

No response