feat(18-01): add the cabana money field (task 1)

- type: money on fields.yaml with currency or currencyFrom, scale (2..4,
  default 4) and max; boot fails naming the field on two sources, none,
  a bad scale or max, a column that is not a string or a Scanner/Valuer,
  or a currencyFrom that is not a string column
- a save answers 422 money.invalid, money.too_precise or money.too_large
  on the field and fills the accepted decimal string unchanged; the same
  check runs on controller, settings and relation child saves
- backend::lang money.* phrases in en and pl
- admin SPA: money.ts (parseMoneyInput, trimMoneyDisplay, formatMoney over
  Intl with the string itself), MoneyField.vue with the currency suffix,
  blur validation and the read-only box, preview through the control,
  the field scope on PreviewView; regenerated OpenAPI and TS types,
  rebuilt modules/boardwalk/dist
- acme.payments fixture with TestMoneyFieldCompile and the Docker
  TestMoneyFieldSmoke; forms.md Money section and cabana README

admin/src/views/PreviewView.vue

@@ -9,7 +9,7 @@ import { controllerIdFromParams, controllerPath } from '../app/controllerRoutes'
 import { message, t } from '../app/i18n'
 import { loadControllerAssets } from '../app/pluginAssets'
 import { newSessionKey } from '../app/sessionKey'
-import { FORM_SESSION, createUploadGate } from '../components/form/formContext'
+import { FIELD_SCOPE, FORM_SESSION, createUploadGate } from '../components/form/formContext'
 import FormTabs from '../components/form/FormTabs.vue'
 import PreviewField from '../components/form/PreviewField.vue'
 import RecordActions from '../components/form/RecordActions.vue'
@@ -193,6 +193,13 @@ function onGone(): void {
 // never uploads or saves, so the session only carries the routes.
 const { activeUploads, beginUpload } = createUploadGate()
 const sessionKey = newSessionKey()
+// A money field reads its currencyFrom sibling through the field scope, as
+// on a form.
+provide(FIELD_SCOPE, {
+  fields: computed(() => fields.value),
+  values: computed(() => values.value),
+  path: (name: string) => name,
+})
 provide(FORM_SESSION, {
   key: sessionKey,
   recordId,