fix(admin): address round-2 review concerns on ImportStatusCard

- Use loop index as each key (handles duplicate filenames)
- Increase skipped filename font from text-xs to text-sm
- Add motion-safe guard to details chevron transition
- Replace text-warning with text-amber-900 to meet WCAG AA contrast

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

frontend/src/routes/admin/system/ImportStatusCard.svelte

@@ -55,10 +55,10 @@ function reasonLabel(code: string): string {
 			<p class="mt-1 text-xs text-green-800">{m.admin_system_import_status_done()}</p>
 		</div>
 		{#if importStatus.skipped > 0}
-			<details class="mb-4 rounded-sm border border-warning/40 bg-warning/10 p-4 text-warning">
+			<details class="mb-4 rounded-sm border border-warning/40 bg-warning/10 p-4 text-amber-900">
 				<summary class="flex cursor-pointer list-none items-center gap-2">
 					<svg
-						class="details-chevron h-4 w-4 shrink-0 transition-transform"
+						class="details-chevron h-4 w-4 shrink-0 motion-safe:transition-transform"
 						viewBox="0 0 16 16"
 						fill="none"
 						stroke="currentColor"
@@ -78,8 +78,10 @@ function reasonLabel(code: string): string {
 					</div>
 				</summary>
 				<ul class="mt-3 space-y-1">
-					{#each importStatus.skippedFiles as { filename, reason } (filename)}
-						<li class="font-mono text-xs text-ink-2">{filename} — {reasonLabel(reason)}</li>
+					{#each importStatus.skippedFiles as skipped, i (i)}
+						<li class="font-mono text-sm text-ink-2">
+							{skipped.filename} — {reasonLabel(skipped.reason)}
+						</li>
 					{/each}
 				</ul>
 			</details>