feature: add necessary shadcn components for CategoryFilter and Sidebar

src/shared/ui/command/command-group.svelte

@@ -0,0 +1,32 @@
+<script lang="ts">
+    import { cn } from '$shared/utils/shadcn-utils.js';
+import { Command as CommandPrimitive, useId } from 'bits-ui';
+
+let {
+    ref = $bindable(null),
+    class: className,
+    children,
+    heading,
+    value,
+    ...restProps
+}: CommandPrimitive.GroupProps & {
+    heading?: string;
+} = $props();
+</script>
+
+<CommandPrimitive.Group
+    bind:ref
+    data-slot="command-group"
+    class={cn('text-foreground overflow-hidden p-1', className)}
+    value={value ?? heading ?? `----${useId()}`}
+    {...restProps}
+>
+    {#if heading}
+        <CommandPrimitive.GroupHeading
+            class="text-muted-foreground px-2 py-1.5 text-xs font-medium"
+        >
+            {heading}
+        </CommandPrimitive.GroupHeading>
+    {/if}
+    <CommandPrimitive.GroupItems {children} />
+</CommandPrimitive.Group>