Copilot round 11. Two of the three are the enum-strip logic this PR added
misbehaving on degenerate input; the third is one more keyword for the
fail-closed rule.
1. An empty `enum` permits nothing at all, but the strip reported "unchanged"
(nothing was removed) and the collapse built a Select with no options — a
required field then had no interaction able to supply a value. It now
reaches the same conclusion as `[null]`: no selectable member, so decline.
The outcome is renamed `unselectable`, since "only-null" no longer describes
both routes to it.
2. Filtering `null` out of `enum` shortens it, which could make an ALREADY
mismatched `enumNames` come out the same length — so `enum: [null, "b"]`
with `enumNames: ["None"]` started labelling `b` as "None", turning labels
both renderers had correctly ignored into a confident mislabel. A list that
was not parallel before filtering is now dropped rather than kept.
3. `$ref` joins the opaque set. It is never resolved here and applies alongside
its siblings, so `{ type: "string", $ref: "#/$defs/intOnly" }` can be
unsatisfiable. The wrapper path already declined on it by virtue of the
annotation allowlist; this extends the same rule to branches, the
`type: [T, "null"]` path, and `admitsNull`.
No round 12 was requested: the review loop was stopped at the user's direction.
Signed-off-by: cliffhall <cliff@futurescale.com>
18053d4cb2