- rootUnion: a merged declaration pairing a `const` with an assertion this
module cannot evaluate (`minimum`, `pattern`, …) is declined. Proving the
conjunction safe is the requirement, not disproving it — `minimum: 10`
beside `const: 1` is as unsatisfiable as a type mismatch.
- declaresAnyFields counts a `$ref`: its shape is unknown rather than empty,
so `anyOf: [{ $ref }, { $ref }]` no longer reports an App tool as
input-free and auto-invokes it with `{}`.
- SchemaForm keys its draft-holding fields by the active branch as well, so a
half-typed `-` or an unparsed JSON draft cannot survive a switch into a
same-named field of the incoming branch — with both parent values
`undefined`, nothing else tells the field the entity changed.
Signed-off-by: cliffhall <cliff@futurescale.com>