user mention (#3771)

src/client/app/desktop/script.ts

@@ -70,6 +70,7 @@ init(async (launch) => {
 				} else {
 					const vm = this.$root.new(PostFormWindow, {
 						reply: o.reply,
+						mention: o.mention,
 						animation: o.animation == null ? true : o.animation
 					});
 					if (o.cb) vm.$once('closed', o.cb);