refactor: tighten the home typography and card craft

The playlist cards were showing "No description was pr…" because the API
stored that English sentence whenever a playlist was created without a
description. Descriptions are optional now and the old rows are cleared.

Section headings drop to 18/20px so they stop competing with the content,
and the space moved from inside the sections to between them.

The three media cards repeated the same anchor, art class and label
block, so they share a MediaCard that also carries the hover lift the
track tiles already had.

web-player/src/routes/login/+page.svelte

@@ -13,10 +13,10 @@
 
 <div class="grid min-h-screen place-items-center bg-bg px-6 text-fg">
 	<div class="flex w-full max-w-110 flex-col items-center gap-9 text-center">
-		<div class="text-3xl font-extrabold tracking-tight">Musify</div>
+		<div class="text-3xl font-semibold tracking-tight">Musify</div>
 
 		<div>
-			<h1 class="text-4xl font-extrabold tracking-tight">Tu música. Sin límites.</h1>
+			<h1 class="text-4xl font-semibold tracking-tight">Tu música. Sin límites.</h1>
 			<p class="mt-3 text-base text-fg-2">Inicia sesión para continuar.</p>
 		</div>