The previous commit's coverage gate failed on `core/json/rootUnion.ts`
branches (89.81%). A property declared with JSON Schema's boolean form has no
keywords to merge, so the two sides agree only by being the same declaration —
now tested both ways, and the dead `baseProperty !== undefined` guard is gone
(`conflicts` is only reached for a name the base declares).
Signed-off-by: cliffhall <cliff@futurescale.com>
d8e9e502be