openDraft's reuse check was `!target.draft`, dead after first render:
createSpawnForm auto-syncs its picked defaults into the leaf's draft
once its project load settles, so every empty pane has a non-null
draft a second later. `n` and Spawn always split instead of reusing
the pane on screen.
Reuse now checks only `!target.sessionId`, matching the codebase's own
definition of "empty" pane elsewhere. Reusing also drops the leaf's
stale form instance so a new seed is read by the rebuilt form instead
of being ignored by the old one.
render() destroyed and rebuilt every draft form, so an unrelated
session exiting tore down a draft mid-edit: focus, caret and
selection were lost and /api/info, /api/projects, /api/names were
refetched for a form already on screen.
Key draft forms by leaf id; rebuild only the pane DOM around them
and destroy a form when its leaf is removed or filled by a session.
The draft pane covers every field the modal had; the modal was a second
code path for the same job. The header Spawn button, sidebar empty state,
welcome button, and ?mock&spawn now open a draft pane via
MultiView.openDraft — reusing an empty focused pane, else splitting it.
"Spawn similar" seeds a draft with the session's cwd + command.
Modal-only CSS (backdrop, sheet/dialog chrome, keyframes) is deleted;
.modal-body form styling folds into .spawn-form, which also picks up the
select styling the worktree branch picker was borrowing from the modal.
Miguel Palhas