CreateDashboard's inline panel-creation path already called
validatePanel before insert; AddPanel and UpdatePanel relied on the
HTTP handler to validate first instead of enforcing it themselves.
Found via a live Postgres integration test: calling store.AddPanel
directly (bypassing the handler) hit a viz_config NOT NULL constraint
violation instead of getting the same default-empty-JSON treatment
every other panel-creation path gets.
jcoffey-dev
5365c92ffa