When starting holos server from the production Deployment, pgbouncer
blocks the automatic migration on startup.
```json
{
"time": "2024-07-16T16:35:52.54507682-07:00",
"level": "ERROR",
"msg": "could not execute",
"version": "0.87.2",
"code": "unknown",
"err": "sql/schema: create \"users\" table: ERROR: permission denied for schema public (SQLSTATE 42501)",
"loc": "cli.go:82"
}
```
This patch separates automatic migration into a `holos server init`
subcommand intended for use in a Job.
Closes: #204
Remove the server.Config struct, not needed. Remove the app struct and
move the configuration to the main holos.Config.ServerConfig.
Add flags specific to server configuration.
With this patch logging is simplified. Subcommands have a handle on the
top level holos.Config and can get a fully configured logger from
cfg.Logger() after flag parsing happens.
Disambiguate the term `core` which should mean the core domain. The app
is a supporting domain concerned with logging and configuration
initialization early in the life cycle.
