[repo:objectui] Form field immutable: true is not enforced on the edit dialog — the lookup stays fully editable after create, while readonly disables required lookups on the create form; no flag delivers create-then-lock #16171

Summary

A form field declared immutable: true (spec: editable on create, locked after the record exists) is honoured only on the create form. On the edit dialog of the same form view the field is still fully editable — the lookup's 「选择…」 picker is enabled (disabled === false), the chip can be cleared, and a new value can be picked. So the only tool an author has to say "this FK is set once and never changes" (readonly breaks create because required lookups become disabled) does nothing on the surface it exists for.

Minimal reproduction

Platform 17.2.0 console.

Object kpi_entry_line with sheet: Field.lookup('kpi_entry_sheet', { required: true }) and plan_indicator: Field.lookup('kpi_plan_indicator', { required: true }). Form view:

formViews: { form: { type: 'simple', data: obj('kpi_entry_line'), sections: [{ name: 'entry', fields: [
  { field: 'sheet', immutable: true }, { field: 'plan_indicator', immutable: true },
  { field: 'actual_value' }, { field: 'remark' }, ...
] }] } }

1. List → 「新建」: both lookups editable, record can be created — correct.
2. Open an existing record → row menu 「编辑」 (or record page edit): both lookups still render as editable lookups; picking another sheet and saving sends the new sheet value.

Control: readonly: true on the same fields locks them on edit but also disables them on the create form, where they are required — the create form then fails with 「所属填报单不能为空」. So neither flag gives "settable once".

Expected

• immutable: true renders the field as read-only (display value, no picker, no clear ✕) whenever the form is bound to an existing record, and as a normal input on create.
• If the console cannot yet distinguish the two modes for a field, the spec should say so, or readonly should stop disabling required fields on create — one of the two flags must deliver the create-then-lock semantics.

Environment

@objectstack/console 17.2.0 · @objectstack/spec 17.2.0 (view.zod.ts FormField immutable) · objectstack dev · Chromium 1440×900 · zh-CN. App: objectstack-ai/kpi (kpi_entry_line form).