- rootUnion: decline a union that adds fields under a restrictive root
`additionalProperties`. The keyword constrains what its SIBLING
`properties` does not name, so the original schema admits none of the
branch fields; flattening moves them beside the keyword, where they read as
allowed and the form would submit what the schema forbids.
- `default` joins the annotation set: it constrains nothing, so two
declarations suggesting different initial values no longer conflict.
- Property records are read with `Object.hasOwn` and built with
`fromEntries`/`defineProperty`. `properties` is a JSON record, so
`constructor` is a legal argument name that `in` reported as a collision
the root never made, and `__proto__` is one that assignment would drop
into the legacy prototype setter instead of keeping as a field.
- SchemaForm: a value survives a branch switch unless BOTH branches declare
the name. A root argument the outgoing branch merely specialized is still a
root argument in a branch that inherits it, so dropping it erased a valid
value.
Signed-off-by: cliffhall <cliff@futurescale.com>
c15e30414f