feat(auth): add org/dept/position management, user page, and Phase 2 completion

Complete Phase 2 identity & authentication module:
- Organization CRUD with tree structure (parent_id + materialized path)
- Department CRUD nested under organizations with tree support
- Position CRUD nested under departments
- User management page with table, create/edit modal, role assignment
- Organization architecture page with 3-panel tree layout
- Frontend API layer for orgs/depts/positions
- Sidebar navigation updated with organization menu item
- Fix parse_ttl edge case for strings ending in 'd' (e.g. "invalid")

apps/web/src/layouts/MainLayout.tsx

@@ -3,6 +3,7 @@ import {
   HomeOutlined,
   UserOutlined,
   SafetyOutlined,
+  ApartmentOutlined,
   BellOutlined,
   SettingOutlined,
   MenuFoldOutlined,
@@ -19,6 +20,7 @@ const menuItems = [
   { key: '/', icon: <HomeOutlined />, label: '首页' },
   { key: '/users', icon: <UserOutlined />, label: '用户管理' },
   { key: '/roles', icon: <SafetyOutlined />, label: '权限管理' },
+  { key: '/organizations', icon: <ApartmentOutlined />, label: '组织架构' },
   { key: '/settings', icon: <SettingOutlined />, label: '系统设置' },
 ];