Initial commit MKD fixes

contexts/PermissionsContext.tsx

@@ -0,0 +1,34 @@
+import React, { createContext, useContext, useMemo } from 'react';
+import { canEditSub, canReadSub, isScopeOwn } from '../constants/permissions';
+
+interface PermissionsContextValue {
+  permissions: string[] | null;
+}
+
+const PermissionsContext = createContext<PermissionsContextValue>({ permissions: null });
+
+export const PermissionsProvider: React.FC<{ permissions: string[] | null; children: React.ReactNode }> = ({
+  permissions,
+  children,
+}) => {
+  const value = useMemo(() => ({ permissions }), [permissions]);
+  return <PermissionsContext.Provider value={value}>{children}</PermissionsContext.Provider>;
+};
+
+export function usePermissions() {
+  return useContext(PermissionsContext);
+}
+
+/** Права на подраздел: можно ли читать, редактировать, только своё */
+export function useSubPermission(section: string, subId: string) {
+  const { permissions } = usePermissions();
+  const list = permissions ?? [];
+  return useMemo(
+    () => ({
+      canRead: canReadSub(list, section, subId),
+      canEdit: canEditSub(list, section, subId),
+      scopeOwn: isScopeOwn(list, section, subId),
+    }),
+    [list, section, subId]
+  );
+}