fix: keep gold btn-primary plate on topic Reply button

The topic-sidebar-tools flattening override was hitting the Reply
button (btn-primary) too, turning it grey. Exclude btn-primary so
Reply keeps the theme's gold plate.

Fixes #34

scss/westgate/_posts.scss

@@ -314,7 +314,8 @@ li[component="post"] [component="post/downvote"] {
 	}
 }
 
-.topic-sidebar-tools .btn,
+// keep the gold .btn-primary plate on Reply; only flatten the tool buttons
+.topic-sidebar-tools .btn:not(.btn-primary),
 [component="topic/navigator"] {
 	background: rgba(255, 255, 255, 0.018) !important;
 	border-color: rgba(194, 163, 90, 0.1) !important;