feature: add necessary shadcn components for CategoryFilter and Sidebar

src/shared/ui/sidebar/sidebar-separator.svelte

@@ -0,0 +1,19 @@
+<script lang="ts">
+    import { Separator } from '$shared/ui/separator/index.js';
+import { cn } from '$shared/utils/shadcn-utils.js';
+import type { ComponentProps } from 'svelte';
+
+let {
+    ref = $bindable(null),
+    class: className,
+    ...restProps
+}: ComponentProps<typeof Separator> = $props();
+</script>
+
+<Separator
+    bind:ref
+    data-slot="sidebar-separator"
+    data-sidebar="separator"
+    class={cn('bg-sidebar-border', className)}
+    {...restProps}
+/>