chore: review vignette endpoint tidy policies

[jonthegeek]

Summary

As a nectar maintainer, in order to keep examples aligned with the new JSON tidier split, I would like to review the vignette endpoints and decide where tidy_policy_json() should be used instead of tidy_policy_json_tibblify().

Details

Review vignettes/nectar.Rmd and verify whether each endpoint shown in examples should use the simpler JSON tidier policy or the tibblify wrapper.

Also confirm that req_body_auto() wasn't impacted by any recent changes.