fix(audio-player): precision rail rendered transparent

Alpine :style string bindings REPLACE the element's style attribute —
the rail's static background/border/z-index were wiped the moment the
binding evaluated, leaving bare text over the transports. Fold all
declarations into the single :style binding.

templates/audio_reader.templ

@@ -241,8 +241,7 @@ templ AudioReader(user User, metadata ReaderMetadata) {
 							x-show="railVisible"
 							x-cloak
 							class="absolute top-full mt-1 inset-x-0 h-12 rounded-lg shadow-lg p-1.5 pointer-events-none"
-							style="background-color: var(--bg-secondary); border: 1px solid var(--border); z-index: 30;"
-							:style="railLiftY ? 'transform: translateY(' + railLiftY + 'px);' : ''"
+							:style="'background-color: var(--bg-secondary); border: 1px solid var(--border); z-index: 30;' + (railLiftY ? ' transform: translateY(' + railLiftY + 'px);' : '')"
 						>
 							<div class="relative h-full">
 								<div class="absolute inset-x-0 top-1/2 h-px" style="background-color: var(--border);"></div>