server: schema validate configurations

Unfortunately there are still many people who prefer static config
file. As such, schema validate the configurations to ensure that
the failure happens loud and early when the config.js is broken.

Also enforces that the length of secret must be larger than 30 as
the JWT secret can be brute forced locally without interaction with
the server.

This ensures that we always have proper configurations and avoids
unnecessary and bad defensive programming practices.

server/models/Users.ts

@@ -5,19 +5,19 @@ import fs from 'fs';
 import path from 'path';
 
 import {AccessLevel} from '../../shared/schema/constants/Auth';
-
-import type {Credentials, UserInDatabase} from '../../shared/schema/Auth';
-
 import config from '../../config';
 import services from '../services';
 
+import type {ClientConnectionSettings} from '../../shared/schema/ClientConnectionSettings';
+import type {Credentials, UserInDatabase} from '../../shared/schema/Auth';
+
 class Users {
   db = Users.loadDatabase();
   configUser: UserInDatabase = {
     _id: '_config',
     username: '_config',
     password: '',
-    client: config.configUser,
+    client: config.configUser as ClientConnectionSettings,
     level: AccessLevel.ADMINISTRATOR,
   };