- `const` constrains a property that is PRESENT; it neither requires the
property nor acts as a default. It is now supplied automatically only where
the schema also requires the field — in `collectSchemaDefaults`,
`applySchemaConstants` and the TUI's initial values alike — so an optional
`dryRun: { const: true }` no longer turns a valid `{}` call into one that
asks the server to do something. A value that IS present is still corrected
to the constant, whatever supplied it, and the field stays read-only.
- Offerability is judged on the base+member merge rather than the raw member,
so `anyOf: [{ required: ["email"] }, { required: ["phone"] }]` over
root-declared properties is offered. It was declined, which left the gate
checking the base alone and accepting `{}` — which that schema rejects.
- The TUI's branch sections keep the schema's own `required` for the seeding
decision while still rendering every branch field non-required, which is what
keeps a static form submittable.
Signed-off-by: cliffhall <cliff@futurescale.com>