Platform configuration options for the window manager.

| Field | Type | Description | Default |
|---|---|---|---|
| `view_id_annotation` | `string` | Specifies the annotation value by which the window manager can identify a view presented by the element it launched on startup, if one is given by \`url\`. |   |
| `url` | `string` | Specifies the Fuchsia package URL of the element the window manager should launch on startup, if one is given. |   |
| `collection` | `string` | Specifies the collection in which the window manager should launch the initial element, if one is given by \`url\`. Defaults to "elements". | elements |