feat(library): genre sliders, artist links, and navigation utils

- music landing: diverse per-genre album sliders (online counts /
  offline wide-probe fallback) and home-screen library shortcuts
- add ArtistLinks component and shared navigation/genreDiversity utils
- player/playback-mode refinements across Rust and frontend

src/routes/library/[id]/+page.svelte

@@ -2,6 +2,7 @@
   import { onMount, untrack } from "svelte";
   import { page } from "$app/stores";
   import { goto } from "$app/navigation";
+  import { navigateBack } from "$lib/utils/navigation";
   import { commands } from "$lib/api/bindings";
   import type { MediaItem, Library } from "$lib/api/types";
   import { library, libraryItems, isLibraryLoading, currentLibrary, libraries } from "$lib/stores/library";
@@ -23,6 +24,8 @@
   import CrewLinks from "$lib/components/library/CrewLinks.svelte";
   import GenreTags from "$lib/components/library/GenreTags.svelte";
   import CachedImage from "$lib/components/common/CachedImage.svelte";
+  import BackButton from "$lib/components/common/BackButton.svelte";
+  import ArtistLinks from "$lib/components/library/ArtistLinks.svelte";
 
   interface SeasonData {
     season: MediaItem;
@@ -281,6 +284,13 @@
     // Navigate to series page without the episode param
     goto(`/library/${itemId}`);
   }
+
+  function goBack() {
+    // Prefer real history so the user returns to wherever they came from
+    // (libraries grid, a list page, a parent album/artist, search, etc.),
+    // falling back to the libraries overview on a fresh deep-link.
+    navigateBack("/library");
+  }
 </script>
 
 <div class="relative">
@@ -315,6 +325,9 @@
   {:else if item}
     <!-- Person Detail View - shown for Person items -->
     {#if item.type === "Person"}
+      <div class="pt-4">
+        <BackButton onClick={goBack} label="Back" />
+      </div>
       <PersonDetailView person={item} />
     <!-- Episode Focus View - shown when navigating with ?episode param -->
     {:else if item.type === "Series" && focusedEpisode}
@@ -326,8 +339,13 @@
       />
     {:else}
     <div class="space-y-8">
+      <!-- Back navigation -->
+      <div class="pt-4">
+        <BackButton onClick={goBack} label="Back" />
+      </div>
+
       <!-- Header with item info -->
-      <div class="flex gap-6 pt-4">
+      <div class="flex gap-6">
         <!-- Poster -->
         <div class="flex-shrink-0 w-48">
           {#if item.primaryImageTag}
@@ -362,10 +380,17 @@
                 {#if item.parentIndexNumber && item.indexNumber}, {/if}
                 {#if item.indexNumber}Episode {item.indexNumber}{/if}
               </p>
-            {:else if item.productionYear || item.artists?.length}
+            {:else if item.artistItems?.length || item.artists?.length}
               <p class="text-lg text-gray-400 mt-1">
-                {item.artists?.join(", ") || item.productionYear}
+                <ArtistLinks
+                  artistItems={item.artistItems}
+                  artists={item.artists}
+                  linkClass="text-lg text-[var(--color-jellyfin)] hover:underline"
+                  textClass="text-gray-400"
+                />
               </p>
+            {:else if item.productionYear}
+              <p class="text-lg text-gray-400 mt-1">{item.productionYear}</p>
             {/if}
           </div>