* assign types to properties
  - db / operation model is just k/v, but formatted names can be used for
    structure:
    - dependencies: `dependency.<uuid> = ""`
    - annotations: `annotation.<epoch time> = "annotation"`
    - tags: `tags.<tag> = ""`
* add HTTP API
* abstract server, storage, etc. into traits
* implement snapshot requests
* implement backups
* implement client-side encryption
* design expiration
  - need to be sure that create / delete operations don't get reversed
* cli tools