[6.x] Fix race condition in blueprint Apply & Save

[jackmcdade]

Closes #13949.

---

Note

Low Risk
Small, localized change to blueprint save timing and callback signature; primary risk is subtle regressions in save triggering/order.

Overview
Fixes a race in blueprint “Apply & Save” by deferring root-form-save handling in Builder.vue to the next tick before calling save(), ensuring child edits are committed first.

Simplifies the save callback by making saved() ignore the Axios response payload and just perform post-save UI cleanup (toast, clear errors, clear dirty state).

^{Written by Cursor Bugbot for commit d124fab. This will update automatically on new commits. Configure here.}