feat: Implement role-based access control and enhance permissions system

app/lib/permissions.ts

@@ -0,0 +1,28 @@
+export const ROLES = {
+  EMPEROR: 'emperor',
+  KNIGHT: 'knight',
+  CIVILIAN: 'civilian',
+} as const;
+
+export type Role = typeof ROLES[keyof typeof ROLES];
+
+export const PERMISSIONS = {
+  MANAGE_EMAIL: 'manage_email',
+  MANAGE_WEBHOOK: 'manage_webhook',
+  PROMOTE_USER: 'promote_user',
+} as const;
+
+export type Permission = typeof PERMISSIONS[keyof typeof PERMISSIONS];
+
+export const ROLE_PERMISSIONS: Record<Role, Permission[]> = {
+  [ROLES.EMPEROR]: Object.values(PERMISSIONS),
+  [ROLES.KNIGHT]: [
+    PERMISSIONS.MANAGE_EMAIL,
+    PERMISSIONS.MANAGE_WEBHOOK,
+  ],
+  [ROLES.CIVILIAN]: [],
+} as const;
+
+export function hasPermission(userRoles: Role[], permission: Permission): boolean {
+  return userRoles.some(role => ROLE_PERMISSIONS[role]?.includes(permission));
+}