Fix usage message in omarchy-branch-set script (#3634)

bin/omarchy-branch-set

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 if (($# == 0)); then
-  echo "Usage: omarchy-channel-set [master|dev]"
+  echo "Usage: omarchy-branch-set [master|dev]"
   exit 1
 else
   branch="$1"