I use 4 spaces for indentation. Go should ideally be formatted with `goimports` and/or `gofmt`. I don't use a formatter on typescript, so don't worry about that.
Code in Go should ideally use `PascalCase` for exported values, and `camelCase` for non-exported, JSON for transferring data should use `snake_case`, and Typescript should use `camelCase`. Forgive me for my many inconsistencies in this, and feel free to fix them if you want.
Functions in Go that need to access `*appContext` should be generally be receivers, except when the behaviour could be seen as somewhat independent from it (`email.go` is the best example, its behaviour is broadly independent from the main app except from a couple config values).