clone_drafts copied every user's drafts, but only the forker gets added
to the fork's usr table. Drafts owned by absent users LEFT-JOIN to NULL
in the home page's draft_users aggregate, surfacing as multiple
legacy-style rows at one path and crashing the popover with
each_key_duplicate. Filter the clone to email = forker OR email IS NULL,
and key the popover's #each by index defensively so future legacy
collisions can't crash the page either.
Also re-adds `draft_only: None` to NewScript/CreateFlowBody literals in
tests — the auto-generated windmill-api-client still carries the field
and the previous commit dropped them too aggressively.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>