Ref T11326. Currently:
- The month view and day view (ghosts) don't show that you're invited to a child event.
- The detail view copies the invite list, including attending status, but only after it shows the page for the first time.
Instead, for now, just do this:
- Ghosts/stubs use the parent invite list, but treat everyone as "invited".
- Materializing a stub just saves the list as-is (i.e., invited, not a copy of attending/declined/etc).
This behavior may need some refining eventually but is at least reasonable (not obviously bad/buggy).