moving audio gain perms around

server/src/services/identityService/permissions.js

@@ -0,0 +1,30 @@
+// Identity Permission Registry
+// Purpose: Defines every positive capability that can be granted to a canonical user.
+// Scope: Keeps stable database keys and operator-facing descriptions centralized so services and admin tools cannot invent mismatched permission names.
+const USER_PERMISSIONS = Object.freeze({
+  'audio.personalAdjustment': Object.freeze({
+    key: 'audio.personalAdjustment',
+    commandName: 'audio-adjustment',
+    label: 'Personal audio adjustment',
+    description: 'Allows personal horn, text-to-speech, and microphone volume adjustments.',
+  }),
+});
+
+function listRegisteredPermissions() {
+  return Object.values(USER_PERMISSIONS).map((permission) => ({ ...permission }));
+}
+
+function requireRegisteredPermission(permissionKey) {
+  const key = String(permissionKey || '').trim().toLowerCase();
+  const permission = Object.values(USER_PERMISSIONS).find((entry) => (
+    entry.key.toLowerCase() === key || entry.commandName.toLowerCase() === key
+  ));
+  if (!permission) throw new Error('Unknown user permission.');
+  return permission;
+}
+
+module.exports = {
+  USER_PERMISSIONS,
+  listRegisteredPermissions,
+  requireRegisteredPermission,
+};