A unified page container component that supports both a legacy layout pattern and an advanced UI pattern with variant-based layouts, headers, back buttons, and configurable actions.
## Key Components
- **`PageContainer`** – Main exported component. Detects which interface is in use via `isAdvancedProps()` and delegates to the appropriate renderer.
- **`LegacyPageContainerProps`** – Backward-compatible interface for full-width background sections with configurable max-width and padding.
- **`AdvancedPageContainerProps`** – Modern interface supporting `variant`, `title`, `subtitle`, `backButton`, `headerActions`, `actions`, and `menuActions`.
- **`renderLegacyPageContainer`** – Preserves original layout behavior with configurable `as` element, background, and padding.
- **`renderAdvancedPageContainer`** – Renders variant-aware layouts (`list`, `detail`, `form`, `content`) with responsive headers and mobile-fixed action bars.
> **Deprecated:** Use `PageLayout` from `'../layout/page-layout'` instead.
## Usage Example
```typescript
// Legacy usage
Content
// Advanced — detail page with back button and actions
router.back() }}
actions={[
{ label: 'Save', onClick: handleSave, variant: 'primary' },
{ label: 'Cancel', onClick: handleCancel },
]}
>
// Advanced — list page with header actions
}
actions={[{ label: 'Add Device', onClick: handleAdd, icon: PlusIcon }]}
>
```
**Source:** [`page-container.tsx`](https://github.com/flamingo-stack/openframe-oss-lib/blob/main/page-container.tsx)