use npm dependencies

packaging/macos/Portfile

@@ -34,7 +34,8 @@ post-fetch {
 depends_lib              port:avahi \
                          port:curl \
                          port:ffmpeg \
-                         port:libopus
+                         port:libopus \
+                         port:npm9
 
 boost.version            1.80
 
@@ -54,6 +55,10 @@ platform darwin {
     }
 }
 
+pre-build {
+    system -W ${worksrcpath}/src_assets/common/assets/web "npm install"
+}
+
 notes-append "Run @PROJECT_NAME@ by executing 'sunshine <path to user config>', e.g. 'sunshine ~/sunshine.conf' "
 notes-append "The config file will be created if it doesn't exist."
 notes-append "It is recommended to set a location for the apps file in the config."