feat(12.2-04): edit related records in modals and defer relation work on new records

- RelationManager renders create/link/delete/unlink in declared order with
  one primary, opens the child modal (update or view form) or the pivot
  modal on row click, and deletes selected children behind a busy confirm
- RelationChildModal creates and edits children with its own session key
  (X-Child-Session-Key) so uploads and dates work inside it
- RelationPivotModal edits link details; the picker links one record with
  its pivot values when the relation has a pivot form
- deferrable managers render on the create screen with owner id 0, the
  form's X-Session-Key and the pending note, and mark the form dirty
- the registry resolves RelationManager lazily (child forms close an
  import cycle); DataTable gains openable rows and a trailing cell
- relation lang keys in en and pl; rebuilt boardwalk dist

admin/src/components/form/registry.ts

@@ -34,6 +34,12 @@ export type { FieldControlProps } from './control'
 /** The relation manager's field type (design screen 5). */
 export const RELATION_MANAGER = 'relation-manager'
 
+// The relation manager renders child forms (FormGrid -> FormField -> this
+// registry), so it sits on an import cycle with this module. It is looked up
+// when a field renders, never while this module evaluates: whichever module
+// of the cycle loads first, the binding is complete by then.
+const lazyRenderers = new Map<string, () => Component>([[RELATION_MANAGER, () => RelationManager]])
+
 const renderers = new Map<string, Component>([
   ['text', TextField],
   ['textarea', TextareaField],
@@ -42,7 +48,6 @@ const renderers = new Map<string, Component>([
   ['switch', SwitchField],
   ['checkbox', CheckboxField],
   ['relation', RelationField],
-  [RELATION_MANAGER, RelationManager],
   ['widget', WidgetField],
   ['partial', PartialField],
   ['fileupload', FileuploadField],
@@ -54,7 +59,8 @@ const selfLabelled = new Set<string>(['switch', 'checkbox', RELATION_MANAGER])
 
 /**
  * Types that need a saved record: never rendered on create (D-05, design
- * screen 5).
+ * screen 5), except a relation manager whose field is deferrable (Phase
+ * 12.2, D-03): FormView keeps it and it works on owner id 0.
  */
 const recordBound = new Set<string>([RELATION_MANAGER])
 
@@ -68,12 +74,12 @@ const valueless = new Set<string>([RELATION_MANAGER, 'widget', 'partial', 'fileu
 const groupLabelledTypes = new Set<string>(['widget', 'partial', 'fileupload'])
 
 export function rendererFor(type: string): Component {
-  return renderers.get(type) ?? UnsupportedField
+  return renderers.get(type) ?? lazyRenderers.get(type)?.() ?? UnsupportedField
 }
 
 /** Whether the SPA can edit values of this field type. */
 export function isRegistered(type: string): boolean {
-  return renderers.has(type) && !valueless.has(type)
+  return (renderers.has(type) || lazyRenderers.has(type)) && !valueless.has(type)
 }
 
 /** Whether a field type renders only on an existing record (relation manager). */