Consolidate .env files. More work on dev containers.

backend/src/staff.ts

@@ -1,6 +1,8 @@
+import { env } from "./env";
+
 /**
  * Zeppelin staff have full access to the dashboard
  */
 export function isStaff(userId: string) {
-  return (process.env.STAFF ?? "").split(",").includes(userId);
+  return (env.STAFF ?? []).includes(userId);
 }