Improve web UI sound deployment

webserver/webserver.go

@@ -193,11 +193,22 @@ func makeCachable(w http.ResponseWriter, p string, fi os.FileInfo, cachable bool
 	cc := normalCacheControl
 	if strings.HasPrefix(p, "/third-party/") {
 		cc = veryCachableCacheControl
+	} else if isFirstPartyWebAsset(p) {
+		cc = "no-cache"
 	}
 
 	w.Header().Set("Cache-Control", cc)
 }
 
+func isFirstPartyWebAsset(p string) bool {
+	switch path.Ext(p) {
+	case ".css", ".html", ".js":
+		return true
+	default:
+		return false
+	}
+}
+
 // fileHandler is our custom reimplementation of http.FileServer
 type fileHandler struct {
 	root http.FileSystem