add per domain settings (#30)

src/entrypoints/popup/pages/site-config/Header.svelte

@@ -0,0 +1,27 @@
+<script lang="ts">
+	import { ArrowLeft } from '@steeze-ui/heroicons';
+	import { Icon } from '@steeze-ui/svelte-icon';
+
+	/* types */
+	interface Props {
+		domain: string;
+		onBackClick: () => void;
+	}
+
+	/* states */
+	let { domain, onBackClick }: Props = $props();
+</script>
+
+<div class="flex items-center gap-2 px-3 py-2.5">
+	<button
+		type="button"
+		class="flex items-center justify-center w-7 h-7 rounded-md text-gray-300 hover:text-gray-100 hover:bg-gray-800/60 cursor-pointer transition-colors"
+		onclick={() => onBackClick()}
+	>
+		<Icon src={ArrowLeft} size="1.1rem" />
+	</button>
+	<div class="min-w-0">
+		<h1 class="text-lg font-semibold text-gray-100 leading-tight">Site settings</h1>
+		<p class="text-xs text-gray-400 leading-tight truncate" title={domain}>{domain}</p>
+	</div>
+</div>