refactor: move activity domain components to lib/activity/

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

frontend/src/lib/activity/ChronikErrorCard.svelte

@@ -0,0 +1,46 @@
+<script lang="ts">
+import * as m from '$lib/paraglide/messages.js';
+
+interface Props {
+	onRetry: () => void;
+	message?: string;
+}
+
+const { onRetry, message }: Props = $props();
+
+const displayMessage: string = $derived(message ?? m.chronik_error_title());
+</script>
+
+<div
+	role="alert"
+	class="flex items-start gap-3 rounded-sm border border-warning/40 bg-warning/10 p-4"
+>
+	<span class="mt-0.5 text-warning-fg" aria-hidden="true">
+		<svg
+			xmlns="http://www.w3.org/2000/svg"
+			class="h-5 w-5"
+			fill="none"
+			viewBox="0 0 24 24"
+			stroke="currentColor"
+			stroke-width="2"
+		>
+			<path
+				stroke-linecap="round"
+				stroke-linejoin="round"
+				d="M12 9v2m0 4h.01M10.29 3.86L1.82 18a2 2 0 001.71 3h16.94a2 2 0 001.71-3L13.71 3.86a2 2 0 00-3.42 0z"
+			/>
+		</svg>
+	</span>
+	<div class="min-w-0 flex-1">
+		<p class="font-sans text-sm text-warning-fg">
+			{displayMessage}
+		</p>
+		<button
+			type="button"
+			onclick={onRetry}
+			class="mt-2 inline-flex items-center rounded-sm bg-warning-fg px-3 py-1 font-sans text-xs font-medium text-surface transition-colors hover:opacity-90 focus-visible:ring-2 focus-visible:ring-focus-ring focus-visible:outline-none"
+		>
+			{m.chronik_error_retry()}
+		</button>
+	</div>
+</div>