Add drag and drop to file manager

svelte/src/filesystem/filemanager/GalleryView.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
 import { fs_node_icon, fs_node_type, fs_encode_path } from "lib/FilesystemAPI.svelte";
-import type { FSNavigator } from "filesystem/FSNavigator";
+import { move_target, type FSNavigator } from "filesystem/FSNavigator";
 import { FileAction, type FileActionHandler } from "./FileManagerLib";
 
 let {
@@ -22,7 +22,9 @@ let {
 		href={"/d"+fs_encode_path(child.path)}
 			onclick={e => file_event(FileAction.Click, index, e)}
 			oncontextmenu={e => file_event(FileAction.Context, index, e)}
-			class:selected={child.fm_selected}
+			ondragstart={e => file_event(FileAction.Drag, index, e)}
+			use:move_target={{nav, node: () => child}}
+			class:selected={$nav.selection.has(child.path)}
 			class:hidden={child.name.startsWith(".") && !show_hidden}
 			class:large_icons
 			title={child.name}
@@ -33,6 +35,7 @@ let {
 				src={fs_node_icon(child, 256, 256)}
 				loading="lazy"
 				alt=""
+				draggable="false"
 			/>
 			<div class="node_name">
 				{child.name}