refactor: move shared components to lib/shared/ sub-packages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/shared/primitives/RichtlinienRuleCard.svelte

@@ -0,0 +1,46 @@
+<script lang="ts">
+type Props = {
+	icon: string;
+	title: string;
+	body: string;
+	beispielInput?: string;
+	beispielInputStrike?: boolean;
+	beispielOutput?: string;
+	beispielLabel?: string;
+};
+
+let {
+	icon,
+	title,
+	body,
+	beispielInput,
+	beispielInputStrike = false,
+	beispielOutput,
+	beispielLabel = 'Beispiel'
+}: Props = $props();
+</script>
+
+<div class="border-brand-sand break-inside-avoid rounded-sm border bg-white p-5 shadow-sm">
+	<div class="mb-3 flex items-center gap-2">
+		<span aria-hidden="true" class="text-xl">{icon}</span>
+		<h3 class="font-serif text-base font-bold text-ink">{title}</h3>
+	</div>
+	<p class="font-serif text-sm leading-relaxed text-ink-2">{body}</p>
+
+	{#if beispielOutput !== undefined}
+		<div class="border-brand-sand mt-4 rounded-sm border bg-parchment px-4 py-3">
+			<p class="font-sans text-xs font-semibold tracking-wider text-ink-3 uppercase">
+				{beispielLabel}
+			</p>
+			<p class="mt-1 font-sans text-sm text-ink">
+				{#if beispielInput !== undefined}
+					<code
+						class={['font-mono', beispielInputStrike && 'line-through'].filter(Boolean).join(' ')}
+						>{beispielInput}</code
+					> →
+				{/if}
+				<code class="font-mono">{beispielOutput}</code>
+			</p>
+		</div>
+	{/if}
+</div>