Fix navbar layout, card spacing, and background hierarchy

- Restore centered DiscDrop branding in navbar
- Navbar bg: base-300 (darkest)
- Cards bg: base-200 (intermediate), hover: base-300 (matches navbar)
- Body bg: base-100 (lightest)
- Card gap increased from gap-4 to gap-6

src/main/resources/templates/fragments/feed-entries.html

@@ -4,10 +4,10 @@
   <p class="text-sm text-base-content/40 mt-2">Add artists to your collection to see their releases here</p>
 </div>
 {#else}
-<div class="flex flex-col gap-4">
+<div class="flex flex-col gap-6">
   {#for entry in entries}
   <a href="https://musicbrainz.org/release-group/{entry.mbid}" target="_blank" rel="noopener noreferrer"
-     class="card card-side bg-base-100 border border-base-300 hover:bg-base-200 transition-colors overflow-hidden">
+     class="card card-side bg-base-200 border border-base-300 hover:bg-base-300 transition-colors shadow-sm overflow-hidden">
     <figure class="w-64">
       <img src="https://coverartarchive.org/release-group/{entry.mbid}/front-250"
            alt="{entry.title}" class="object-cover w-full h-full"

src/main/resources/templates/fragments/search-results.html

@@ -1,4 +1,4 @@
-<div class="bg-base-100 shadow-xl border border-base-300 rounded-box mt-1" style="max-height:24rem;overflow-y:auto">
+<div class="bg-base-200 shadow-xl border border-base-300 rounded-box mt-1" style="max-height:24rem;overflow-y:auto">
   {#if artists.isEmpty()}
     <div class="p-6 text-sm text-center" style="color:var(--bc);opacity:0.5">No artists found</div>
   {#else}