feat(web-player): add the albums pages

A grid of your albums with a create dialog, and a detail page with the
tracklist, inline editing and a picker that lists the songs you uploaded so
they can be dropped into the album. Covers reuse the playlist mosaic since an
album has no artwork of its own yet.

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

@@ -4,6 +4,7 @@
 	import Home from '@lucide/svelte/icons/house';
 	import Search from '@lucide/svelte/icons/search';
 	import Folder from '@lucide/svelte/icons/folder';
+	import Disc from '@lucide/svelte/icons/disc-3';
 	import Music from '@lucide/svelte/icons/music';
 	import Upload from '@lucide/svelte/icons/upload';
 	import LogOut from '@lucide/svelte/icons/log-out';
@@ -35,6 +36,7 @@
 	];
 
 	const secondaryLinks = [
+		{ href: '/albums', label: 'Mis álbumes', icon: Disc },
 		{ href: '/library', label: 'Canciones subidas', icon: Folder },
 		{ href: '/upload', label: 'Subir música', icon: Upload }
 	];

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

@@ -0,0 +1,35 @@
+<script lang="ts">
+	import PlaylistArt from './PlaylistArt.svelte';
+	import { hueFor } from '$lib/theme/color';
+
+	interface Props {
+		id: string;
+		title: string;
+		releaseYear?: number;
+		trackCount: number;
+		trackIds: (string | number)[];
+		index?: number;
+	}
+
+	let { id, title, releaseYear, trackCount, trackIds, index = 0 }: Props = $props();
+
+	const meta = $derived(
+		[releaseYear, `${trackCount} ${trackCount === 1 ? 'canción' : 'canciones'}`]
+			.filter((part) => part !== undefined && part !== null)
+			.join(' · ')
+	);
+</script>
+
+<a
+	href="/albums/{id}"
+	class="group animate-enter min-w-0 text-left"
+	style="animation-delay:{index * 45}ms"
+>
+	<PlaylistArt
+		{trackIds}
+		hue={hueFor(id)}
+		class="aspect-square w-full rounded-art shadow-art transition group-hover:shadow-art-lg"
+	/>
+	<div class="mt-2.5 truncate text-fg">{title}</div>
+	<div class="mt-0.5 truncate text-sm text-fg-3">{meta}</div>
+</a>

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

@@ -0,0 +1,101 @@
+<script lang="ts">
+	import { untrack } from 'svelte';
+	import { enhance } from '$app/forms';
+	import Button from './Button.svelte';
+	import Field from './Field.svelte';
+	import Input from './Input.svelte';
+	import Textarea from './Textarea.svelte';
+	import Alert from './Alert.svelte';
+	import { ALBUM_EARLIEST_YEAR } from '$lib/config';
+
+	interface Props {
+		action: string;
+		initialTitle?: string;
+		initialDescription?: string;
+		initialReleaseYear?: number;
+		titlePlaceholder?: string;
+		formMessage?: string;
+		submitLabel: string;
+		submittingLabel: string;
+		onCancel: () => void;
+		onSuccess?: () => void;
+	}
+
+	let {
+		action,
+		initialTitle = '',
+		initialDescription = '',
+		initialReleaseYear,
+		titlePlaceholder = '',
+		formMessage,
+		submitLabel,
+		submittingLabel,
+		onCancel,
+		onSuccess
+	}: Props = $props();
+
+	let title = $state(untrack(() => initialTitle));
+	let description = $state(untrack(() => initialDescription));
+	let releaseYear = $state(untrack(() => (initialReleaseYear ? String(initialReleaseYear) : '')));
+	let submitting = $state(false);
+
+	const latestYear = new Date().getFullYear() + 1;
+</script>
+
+<form
+	method="POST"
+	{action}
+	use:enhance={() => {
+		submitting = true;
+		return async ({ update, result }) => {
+			await update({ reset: false });
+			submitting = false;
+			if (result.type === 'success') onSuccess?.();
+		};
+	}}
+	class="mt-4 w-full max-w-2xl space-y-4"
+>
+	<Field label="Título" for="album-title">
+		<Input
+			id="album-title"
+			name="title"
+			maxlength={200}
+			required
+			bind:value={title}
+			placeholder={titlePlaceholder}
+		/>
+	</Field>
+
+	<Field label="Año de publicación" for="album-year" optional>
+		<Input
+			id="album-year"
+			name="releaseYear"
+			type="number"
+			min={ALBUM_EARLIEST_YEAR}
+			max={latestYear}
+			bind:value={releaseYear}
+			placeholder={String(new Date().getFullYear())}
+		/>
+	</Field>
+
+	<Field label="Descripción" for="album-description" optional>
+		<Textarea
+			id="album-description"
+			name="description"
+			maxlength={256}
+			bind:value={description}
+			placeholder="¿De qué va este álbum?"
+		/>
+	</Field>
+
+	{#if formMessage}
+		<Alert tone="danger">{formMessage}</Alert>
+	{/if}
+
+	<div class="flex items-center justify-end gap-3">
+		<Button type="button" variant="secondary" onclick={onCancel}>Cancelar</Button>
+		<Button type="submit" disabled={submitting || title.trim() === ''}>
+			{submitting ? submittingLabel : submitLabel}
+		</Button>
+	</div>
+</form>