refactor(client): Phase 8 consolidate form state with useReducer and key resets

- 8.1: documents-section.tsx - 5 useState → 1 useReducer
- 8.2: role-org-chart.tsx - 5 useState → 1 useReducer
- 8.3: Replace useEffect reset with key prop remount in 3 dialogs
  - role-detail-modal.tsx: key={role.id}
  - rule-editor-dialog.tsx: key={initialRule?.permission_id ?? 'new'}
  - export-chart-dialog.tsx: key={dialogKey} counter
- Removed eslint-disable in rule-editor-dialog.tsx