feature: move all shadcn related code to src/shared/shadcn

src/shared/shadcn/ui/sidebar/sidebar-rail.svelte

@@ -0,0 +1,36 @@
+<script lang="ts">
+    import { cn, type WithElementRef } from '$shared/shadcn/utils/shadcn-utils.js';
+import type { HTMLAttributes } from 'svelte/elements';
+import { useSidebar } from './context.svelte.js';
+
+let {
+    ref = $bindable(null),
+    class: className,
+    children,
+    ...restProps
+}: WithElementRef<HTMLAttributes<HTMLButtonElement>, HTMLButtonElement> = $props();
+
+const sidebar = useSidebar();
+</script>
+
+<button
+    bind:this={ref}
+    data-sidebar="rail"
+    data-slot="sidebar-rail"
+    aria-label="Toggle Sidebar"
+    tabIndex={-1}
+    onclick={sidebar.toggle}
+    title="Toggle Sidebar"
+    class={cn(
+        'hover:after:bg-sidebar-border absolute inset-y-0 z-20 hidden w-4 -translate-x-1/2 transition-all ease-linear group-data-[side=left]:-end-4 group-data-[side=right]:start-0 after:absolute after:inset-y-0 after:start-[calc(1/2*100%-1px)] after:w-[2px] sm:flex',
+        'in-data-[side=left]:cursor-w-resize in-data-[side=right]:cursor-e-resize',
+        '[[data-side=left][data-state=collapsed]_&]:cursor-e-resize [[data-side=right][data-state=collapsed]_&]:cursor-w-resize',
+        'hover:group-data-[collapsible=offcanvas]:bg-sidebar group-data-[collapsible=offcanvas]:translate-x-0 group-data-[collapsible=offcanvas]:after:start-full',
+        '[[data-side=left][data-collapsible=offcanvas]_&]:-end-2',
+        '[[data-side=right][data-collapsible=offcanvas]_&]:-start-2',
+        className,
+    )}
+    {...restProps}
+>
+    {@render children?.()}
+</button>