fix(suggestions): hide section entirely when no suggestions available

Instead of showing 'No suggestions available' message, the entire
suggestions section is now hidden when there are no results.
Better UX - less frustrating for users.

src/lib/components/PlaylistSuggestions.svelte

@@ -181,7 +181,7 @@
   }
 </script>
 
-{#if artists.length > 0}
+{#if artists.length > 0 && !isEmpty}
   <div class="suggestions-section" id="suggestions-anchor">
     <div class="suggestions-header">
       <div class="header-left">
@@ -214,11 +214,6 @@
         <p>{error}</p>
         <button onclick={() => loadSuggestions(false)}>Retry</button>
       </div>
-    {:else if isEmpty}
-      <div class="empty-state">
-        <p>No suggestions available for this playlist.</p>
-        <p class="hint">Try adding more tracks with different artists.</p>
-      </div>
     {:else}
       <div class="suggestions-list">
         {#each visibleTracks as track (track.track_id)}
@@ -371,8 +366,7 @@
   }
 
   .loading-state,
-  .error-state,
-  .empty-state {
+  .error-state {
     display: flex;
     flex-direction: column;
     align-items: center;
@@ -403,11 +397,6 @@
     font-size: 13px;
   }
 
-  .empty-state .hint {
-    font-size: 12px;
-    margin-top: 4px;
-  }
-
   .suggestions-list {
     display: flex;
     flex-direction: column;