Handle missing user & dev.user namespaces

src/dev/user.cljs

@@ -0,0 +1,2 @@
+;; Placeholder namespace. Replace it at your own discretion.
+(ns dev.user)

src/user.cljs

@@ -0,0 +1,2 @@
+;; Placeholder namespace. Replace it at your own discretion.
+(ns user)