[ui] various gallery ui improvements

smaller thumbnails by default
align to "baseline" to help scanning

webui/src/components/display/BlobPreview.svelte

@@ -94,7 +94,7 @@
   }
 
   .hashbadge {
-    font-size: 64px;
+    font-size: 48px;
     opacity: 0.25;
     text-align: center;
   }

webui/src/components/widgets/Gallery.svelte

@@ -116,19 +116,19 @@
   .thumbnail {
     border: 1px solid var(--foreground);
     border-radius: 4px;
-    padding: 0.5em;
+    padding: 0.25em;
   }
 
   .gallery {
     display: flex;
     gap: 1rem;
     flex-wrap: wrap;
-    align-items: center;
+    align-items: flex-end;
   }
 
   .thumbnail {
     flex-grow: 1;
     min-width: 0;
-    flex-basis: 512px;
+    flex-basis: 20%;
   }
 </style>