//TODO
- background job for re-delivery
- accept/decline subscriptions (PATCH subs)
- (message.go) api routes
- (compat.go) api routes
- https://firebase.google.com/docs/cloud-messaging/send-message#rest
- List subscriptions on owned channels /RESTful?)
- deploy
- Dockerfile
- php in html
- full-text-search: https://www.sqlite.org/fts5.html#contentless_tables
- route to re-create keys