fix(TranscribeCoachEmptyState): Tailwind grid instead of inline styles; step aria-labels

- Replace style="grid-template-columns: 34px 1fr; align-items: start;"
  with Tailwind grid-cols-[34px_1fr] items-start (Felix: inline styles)
- Add aria-label="Schritt N von 3" on each <li> so screen readers announce
  step position when the numeric badge is aria-hidden (Nora/Sara)

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

frontend/src/lib/components/TranscribeCoachEmptyState.svelte

@@ -13,7 +13,7 @@ import TranscribeDragDemo from './TranscribeDragDemo.svelte';
 
 	<ol class="m-0 flex list-none flex-col gap-[18px] p-0">
 		<!-- Step 1 -->
-		<li class="grid gap-3.5" style="grid-template-columns: 34px 1fr; align-items: start;">
+		<li aria-label="Schritt 1 von 3" class="grid grid-cols-[34px_1fr] items-start gap-3.5">
 			<span
 				aria-hidden="true"
 				class="flex h-7 w-7 flex-shrink-0 items-center justify-center rounded-full bg-ink font-sans text-sm font-bold text-white"
@@ -27,7 +27,7 @@ import TranscribeDragDemo from './TranscribeDragDemo.svelte';
 		</li>
 
 		<!-- Step 2 -->
-		<li class="grid gap-3.5" style="grid-template-columns: 34px 1fr; align-items: start;">
+		<li aria-label="Schritt 2 von 3" class="grid grid-cols-[34px_1fr] items-start gap-3.5">
 			<span
 				aria-hidden="true"
 				class="flex h-7 w-7 flex-shrink-0 items-center justify-center rounded-full bg-ink font-sans text-sm font-bold text-white"
@@ -40,7 +40,7 @@ import TranscribeDragDemo from './TranscribeDragDemo.svelte';
 		</li>
 
 		<!-- Step 3 -->
-		<li class="grid gap-3.5" style="grid-template-columns: 34px 1fr; align-items: start;">
+		<li aria-label="Schritt 3 von 3" class="grid grid-cols-[34px_1fr] items-start gap-3.5">
 			<span
 				aria-hidden="true"
 				class="flex h-7 w-7 flex-shrink-0 items-center justify-center rounded-full bg-ink font-sans text-sm font-bold text-white"