feat(10.1-02): render header and form partials through an allowlisted node renderer

- partialNodes rebuilds the server node tree with h() under the server's tag, attribute and URL lists
- PartialHost owns the skeleton, empty and failure states and keeps nodes visible on refetch
- type: partial is a valueless group-labelled field rendered on create and update
- ListView shows headerPartial above the list card and refetches it after bulk delete
- summer-partial and summer-stats style kit in main.css, documented in the cabana README; dist rebuilt

admin/src/api/types.ts

@@ -40,6 +40,10 @@ export type AdminActionRequest = Schemas['cabana.AdminActionRequest']
 export type AdminActionResult = Schemas['cabana.AdminActionResult']
 /** A controller's plugin script and stylesheet URLs under {base}/assets/. */
 export type ControllerAssets = Schemas['cabana.ControllerAssets']
+/** One node of a rendered partial: an allowlisted element or a text node. */
+export type PartialNode = Schemas['cabana.PartialNode']
+/** A rendered header or form partial. */
+export type PartialView = Schemas['cabana.PartialView']
 /** One message as CLDR plural forms; "other" is always present (D-13). */
 export type MessageForms = Schemas['cabana.MessageForms']
 /** The public backend::lang bundle: full key to CLDR forms (D-20). */