Render buttons with the data needed to locate click handlers

TODO

@@ -2,6 +2,8 @@
 
 - path to event listener:
 
+  - rerender w/ a signal to branch into handler
+  - capture correct position information in script blocks
   - card fields (vars maybe not needed yet?)
     - set field command
       - buffer output/side-effects in VM
@@ -9,8 +11,6 @@
         - unit test
       - command
       - set field inline instead of separate data???
-  - capture VM status (variables, procs?)?
-    - or is it sufficient to rerender w/ a signal to branch into handler?
 
 - impl vars