feat(19.6.1-02): field trigger and admin build

- fields.yaml trigger (action disable|hide, field, condition checked|unchecked) compiled to FormField.Trigger
- boot errors for malformed triggers, controlling fields that are not a switch or checkbox, and triggers in repeater rows, settings and relation forms
- Administrators permissions overrides are disabled while Superuser is on (D-06)
- SPA: trigger.ts (triggerState, applyTriggers), FORM_TRIGGER_NOTES, the trigger note in FormField, FormView tabs/banner/payload after triggers, PreviewView hide only
- regenerated admin OpenAPI and schema.d.ts; rebuilt modules/boardwalk/dist; docs and README

admin/src/components/form/formContext.ts

@@ -99,6 +99,13 @@ export const SETTINGS_SECRETS: InjectionKey<Readonly<Ref<Record<string, string>>
 export const FORM_PERMISSION_LOCKS: InjectionKey<Readonly<Ref<Record<string, PermissionRecordLock[]>>>> =
   Symbol('summer.form.permissionLocks')
 
+/**
+ * The notes of the fields a trigger disables now (fields.yaml `trigger`,
+ * D-21): top-level field name to the note shown between the label and the
+ * control. FormView provides it; without a provider no note is shown.
+ */
+export const FORM_TRIGGER_NOTES: InjectionKey<Readonly<Ref<Record<string, string>>>> = Symbol('summer.form.triggerNotes')
+
 /** Event a widget element dispatches to run its action (bubbles, composed). */
 export const WIDGET_EVENT = 'summer-action'