Add a dropdown for resource selection and adopt it in the 'Image' node (#4543)

* Add a dropdown for resource selection and adopt it in the Image node

* Route every image upload through a new ResourceUpload handler with desktop support and migrate wired 'Image' node inputs

* Show each resource's user count in the resource picker dropdown

* Send a picked resource file to the document that requested it, list every non-font resource in the picker, and link sibling message docs

node-graph/graph-craft/src/document/value.rs

@@ -42,6 +42,7 @@ macro_rules! for_each_item_type_default {
 		$action!(Gradient);
 		$action!(Artboard);
 		$action!(String);
+		$action!(Resource);
 	};
 }
 
@@ -63,7 +64,6 @@ macro_rules! for_each_list_type_default {
 macro_rules! for_each_bare_type_default {
 	($action:ident) => {
 		$action!(DocumentNode);
-		$action!(Resource);
 	};
 }
 

node-graph/nodes/raster/src/std_nodes.rs

@@ -251,13 +251,17 @@ pub fn empty_image(_: impl Ctx, transform: Item<DAffine2>, color: Item<Color>) -
 }
 
 #[node_macro::node(category(""))]
-pub fn image<'a: 'n>(_: impl Ctx, resource: Item<Resource>) -> Item<Raster<CPU>> {
+pub fn image<'a: 'n>(
+	_: impl Ctx,
+	_primary: (),
+	/// The image file to display.
+	#[widget(ParsedWidgetOverride::Custom = "image_file")]
+	resource: Item<Resource>,
+) -> Item<Raster<CPU>> {
 	let resource = resource.into_element();
 	let image_data = resource.as_ref();
 
-	let Some(image) = ::image::load_from_memory(image_data).ok() else {
-		return Item::default();
-	};
+	let Some(image) = ::image::load_from_memory(image_data).ok() else { return Item::default() };
 	let image = image.to_rgba32f();
 	let image = Image {
 		data: image.chunks(4).map(|pixel| Color::from_gamma_srgb_channels(pixel[0], pixel[1], pixel[2], pixel[3])).collect(),