Let users browse followers and following lists

Following lists are public; followers are visible to the user and to mutual followers.
Adds GET /users/{id}/followers and /following, exposes isFollowing and canViewFollowers
on the profile, and returns isFollowedByViewer from user search so the web player no
longer calls /is-following per user.

web-player/src/routes/(app)/explore/+page.svelte

@@ -10,7 +10,7 @@
 	import InfiniteScroll from '$lib/components/ui/primitives/InfiniteScroll.svelte';
 	import Artwork from '$lib/components/ui/media/Artwork.svelte';
 	import Avatar from '$lib/components/ui/media/Avatar.svelte';
-	import FollowButton from '$lib/components/ui/media/FollowButton.svelte';
+	import UserRow from '$lib/components/ui/media/UserRow.svelte';
 	import PlayButton from '$lib/components/ui/media/PlayButton.svelte';
 	import EqBars from '$lib/components/ui/media/EqBars.svelte';
 	import ListRow from '$lib/components/ui/media/ListRow.svelte';
@@ -402,15 +402,8 @@
 					<SectionHeading title="Usuarios" count={counts.Usuarios} />
 					<ul class="flex flex-col gap-1">
 						{#each capped(sfilter, users) as u (u.id)}
-							<li class="flex items-center gap-3">
-								<ListRow title={u.name} href="/user/{u.id}" size="lg" class="min-w-0 flex-1">
-									{#snippet art()}
-										<Avatar name={u.name} src={u.profilePictureUrl} size="md" />
-									{/snippet}
-								</ListRow>
-								{#if data.canFollow && !u.isSelf}
-									<FollowButton following={u.isFollowing} userId={u.id} class="shrink-0" />
-								{/if}
+							<li>
+								<UserRow user={u} canFollow={data.viewerId !== null && data.viewerId !== u.id} />
 							</li>
 						{/each}
 					</ul>