When formatting arrays of objects that have no own enumerable keys as
Markdown, formatObjectTable derives empty headers and outputs a malformed
table with an invalid delimiter row. Require at least one item with keys in
isObjectArray and fall back to JSON serialization when headers are empty.
Fixes#7057
Preserve boundary facts and uncertainty through their consumers. Add focused production-boundary regressions and update affected documentation.
Fixes#6756Fixes#6752Fixes#6755