Add MineGeo gameplay systems and interface

shared/permissions.ts

@@ -0,0 +1,10 @@
+export type AccountRole = "contributor" | "moderator" | "admin";
+export type StaffRole = Exclude<AccountRole, "contributor">;
+
+export function canReviewMaps(role: string | undefined): role is StaffRole {
+  return role === "moderator" || role === "admin";
+}
+
+export function isAdministrator(role: string | undefined) {
+  return role === "admin";
+}