viewer: update sunlight settings (#9846)

Missing the castShadows=true caused the shadows to be missing
on mobile (using the remote settings page).

Update README.md (this will trigger an update to the remote
page's filament.js)

libs/viewer/README.md

@@ -20,10 +20,10 @@ The root object contains the following categories:
 | Key | Type | Description |
 | :--- | :--- | :--- |
 | `view` | Object | Post-processing and rendering quality settings. |
-| `camera` | Object | **[NEW]** Explicit camera control (pose, projection, exposure). |
-| `lighting` | Object | **[NEW]** Environment and dynamic light settings. |
+| `camera` | Object | Explicit camera control (pose, projection, exposure). |
+| `lighting` | Object | Environment and dynamic light settings. |
 | `viewer` | Object | Global viewer options (skybox, background, scaling). |
-| `animation` | Object | **[NEW]** Animation playback control. |
+| `animation` | Object | Animation playback control. |
 | `material` | Object | Material overrides. |
 
 ---

libs/viewer/include/viewer/Settings.h

@@ -262,6 +262,7 @@ struct LightSettings {
           .direction  = {0.6, -1.0, -0.8},
           .color = filament::Color::toLinear<filament::ACCURATE>({ 0.98, 0.92, 0.89}),
           .intensity = 100000.0f,
+          .castShadows = true,
     };
     std::vector<LightDefinition> lights;
 };