feat(12.1-02): read-only preview screen with a status hint and record actions

- config_form.yaml preview block (optional headerPartial), reported in the form schema as preview
- fields with context: preview show only on the preview screen and are never written
- form messages preview and edit; recordActions without a preview block stops boot
- SPA route {id}/preview, PreviewView and PreviewField, record actions in the footer
- mapWinterUrl maps preview/:id; the update form returns to the preview
- summer-callout partial style classes for status hints
- README, docs, OpenAPI document, TS types and the embedded build updated

modules/cabana/testdata/roster/lang/en/lang.yaml

@@ -15,3 +15,12 @@ people:
   refused: You may not rename this person.
   refused_name: This name is reserved.
   locked: This person is locked and cannot be changed.
+  preview: Person details
+  edit: Edit person
+  joined_ip: Joined from IP address
+  banned_title: This person is banned
+  banned_text: A banned person cannot sign in until the ban is lifted.
+  deleted_title: This person is archived
+  deleted_text: An archived person is hidden from the directory.
+  inactive_title: This person is not active
+  inactive_text: Activate the person to let them sign in.