Remove YouTube integration from web-player; unify Home track rows

Drops every YouTube-backed route, proxy and type (external
albums/tracks, thumbnail proxy, youtube.ts) and simplifies
player/track/mix types to the local-only catalog now that the
backend contract dropped Source/ExternalId. Genre tiles on Explore
and "Populares esta semana" on Home stay as deliberate client-only
placeholders per product decision, just without the YouTube backing.

Also finishes the design-system unification pass: Home's three
hand-rolled track rows (Continuar escuchando, Playlist destacada,
Populares esta semana) now reuse the shared TrackTitleCell component
instead of duplicating cover+title+artist markup, and the orphaned
Rail.svelte (no importers) is removed.

web-player/src/lib/components/AlbumContextMenu.svelte

@@ -2,18 +2,11 @@
 	const MENU_WIDTH = 240;
 	const SUBMENU_WIDTH = 256;
 
-	export type AlbumMenuState = { x: number; y: number; openLeft: boolean } & (
-		{ kind: 'local'; albumId: string } | { kind: 'youtube'; albumId: string }
-	);
+	export type AlbumMenuState = { x: number; y: number; openLeft: boolean; albumId: string };
 
-	export function albumContextMenuStateFor(
-		event: MouseEvent,
-		kind: 'local' | 'youtube',
-		albumId: string
-	): AlbumMenuState {
+	export function albumContextMenuStateFor(event: MouseEvent, albumId: string): AlbumMenuState {
 		event.preventDefault();
 		return {
-			kind,
 			albumId,
 			x: Math.max(8, Math.min(event.clientX, window.innerWidth - MENU_WIDTH - 8)),
 			y: Math.max(8, Math.min(event.clientY, window.innerHeight - 60)),
@@ -93,9 +86,7 @@
 						{#each playlists as playlist (playlist.id)}
 							<form
 								method="POST"
-								action={menu.kind === 'youtube'
-									? '?/addYoutubeAlbumToPlaylist'
-									: '?/addAlbumToPlaylist'}
+								action="?/addAlbumToPlaylist"
 								use:enhance={() =>
 									({ update }) => {
 										onClose();

web-player/src/lib/components/TrackContextMenu.svelte

@@ -78,7 +78,7 @@
 						{#each playlists as playlist (playlist.id)}
 							<form
 								method="POST"
-								action={menu.kind === 'youtube' ? '?/addYouTubeToPlaylist' : '?/addTrack'}
+								action="?/addTrack"
 								use:enhance={() =>
 									({ update }) => {
 										onClose();
@@ -86,15 +86,7 @@
 									}}
 							>
 								<input type="hidden" name="playlistId" value={playlist.id} />
-								{#if menu.kind === 'youtube'}
-									<input type="hidden" name="videoId" value={menu.song.videoId} />
-									<input type="hidden" name="title" value={menu.song.title} />
-									<input type="hidden" name="artist" value={menu.song.artist} />
-									<input type="hidden" name="durationSeconds" value={menu.song.durationSeconds} />
-									<input type="hidden" name="thumbnailUrl" value={menu.song.thumbnailUrl} />
-								{:else}
-									<input type="hidden" name="trackId" value={menu.track.id} />
-								{/if}
+								<input type="hidden" name="trackId" value={menu.track.id} />
 								<button
 									type="submit"
 									class="flex w-full items-center gap-3 rounded-control px-2 py-2.5 text-left text-sm font-medium text-fg transition hover:bg-hover"

web-player/src/lib/components/player/Queue.svelte

@@ -39,7 +39,6 @@
 			<div class="mb-6 flex items-center gap-3 rounded-xl bg-accent-tint p-2.5">
 				<Cover
 					trackId={player.current.id}
-					src={player.current.coverUrl}
 					size="small"
 					alt={player.current.title}
 					class="h-10 w-10 shrink-0 rounded-[9px]"
@@ -90,7 +89,6 @@
 				>
 					<Cover
 						trackId={track.id}
-						src={track.coverUrl}
 						size="small"
 						alt={track.title}
 						class="h-9 w-9 shrink-0 rounded-lg opacity-90"
@@ -104,9 +102,7 @@
 						/>
 					</div>
 					{#if track.duration}
-						<span class="shrink-0 text-xs text-muted tabular-nums"
-							>{fmtTime(track.duration)}</span
-						>
+						<span class="shrink-0 text-xs text-muted tabular-nums">{fmtTime(track.duration)}</span>
 					{/if}
 				</div>
 			{:else}

web-player/src/lib/components/player/TrackInfo.svelte

@@ -20,8 +20,6 @@
 			id: player.current.id,
 			title: player.current.title,
 			artist: player.current.artist,
-			coverUrl: player.current.coverUrl,
-			source: player.current.source,
 			explicit: player.current.explicit,
 			ownerUserId: player.current.ownerUserId
 		});
@@ -32,7 +30,6 @@
 	{#if player.current.id}
 		<Cover
 			trackId={player.current.id}
-			src={player.current.coverUrl}
 			size="small"
 			alt={player.current.title}
 			class="h-11 w-11 shrink-0 rounded-[11px] shadow-cover-xs md:h-12 md:w-12"

web-player/src/lib/components/ui/Cover.svelte

@@ -1,6 +1,5 @@
 <script lang="ts">
 	import type { Snippet } from 'svelte';
-	import { thumbnailSrc } from '$lib/thumbnails';
 
 	interface Props {
 		trackId: string | number;
@@ -24,9 +23,7 @@
 
 	let failed = $state(false);
 
-	const imageSrc = $derived(
-		src ? (thumbnailSrc(src, size) ?? src) : `/api/tracks/${trackId}/cover?size=${size}`
-	);
+	const imageSrc = $derived(src ?? `/api/tracks/${trackId}/cover?size=${size}`);
 
 	$effect(() => {
 		imageSrc;

web-player/src/lib/components/ui/MixArt.svelte

@@ -15,21 +15,11 @@
 {#if tiles.length >= 4}
 	<div class="grid grid-cols-2 grid-rows-2 overflow-hidden {klass}">
 		{#each tiles as item (mixItemKey(item))}
-			<Cover
-				trackId={item.trackId ?? item.videoId ?? ''}
-				src={item.thumbnailUrl}
-				size="small"
-				class="h-full w-full"
-			/>
+			<Cover trackId={item.trackId} size="small" class="h-full w-full" />
 		{/each}
 	</div>
 {:else if tiles.length > 0}
-	<Cover
-		trackId={tiles[0].trackId ?? tiles[0].videoId ?? ''}
-		src={tiles[0].thumbnailUrl}
-		size="medium"
-		class={klass}
-	/>
+	<Cover trackId={tiles[0].trackId} size="medium" class={klass} />
 {:else}
 	<div class="bg-surface {klass}"></div>
 {/if}

web-player/src/lib/components/ui/Rail.svelte

@@ -1,29 +0,0 @@
-<script lang="ts">
-	import type { Snippet } from 'svelte';
-
-	interface Props {
-		class?: string;
-		children: Snippet;
-	}
-
-	let { class: klass = '', children }: Props = $props();
-
-	let track: HTMLDivElement | undefined = $state();
-
-	export function scrollByPage(direction: 1 | -1) {
-		track?.scrollBy({ left: direction * track.clientWidth * 0.85, behavior: 'smooth' });
-	}
-</script>
-
-<div bind:this={track} class="no-scrollbar -mx-1 flex gap-4 overflow-x-auto px-1 pb-2 {klass}">
-	{@render children()}
-</div>
-
-<style>
-	.no-scrollbar {
-		scrollbar-width: none;
-	}
-	.no-scrollbar::-webkit-scrollbar {
-		display: none;
-	}
-</style>