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/components/form/FormField.vue

@@ -39,10 +39,10 @@ const describedBy = computed(() =>
 
 <template>
   <div class="flex min-w-0 flex-col gap-1.5" :data-field="field.name">
-    <span v-if="labelsGroup" :id="`${controlId}-label`" class="font-semibold">
-      {{ field.label || field.name }}<span v-if="field.required" class="text-danger" aria-hidden="true"> *</span>
+    <span v-if="labelsGroup && field.label" :id="`${controlId}-label`" class="font-semibold">
+      {{ field.label }}<span v-if="field.required" class="text-danger" aria-hidden="true"> *</span>
     </span>
-    <label v-else-if="!selfLabelled" :for="controlId" class="font-semibold">
+    <label v-else-if="!selfLabelled && !labelsGroup" :for="controlId" class="font-semibold">
       {{ field.label || field.name }}<span v-if="field.required" class="text-danger" aria-hidden="true"> *</span>
     </label>
     <FieldRenderer

admin/src/components/form/fields/PartialField.vue

@@ -0,0 +1,31 @@
+<script setup lang="ts">
+import { t } from '../../../app/i18n'
+import PartialHost from '../../partial/PartialHost.vue'
+import ExtensionFailure from '../../ui/ExtensionFailure.vue'
+import type { FieldControlProps } from '../control'
+
+// A `type: partial` form row (D-09; UI-SPEC S2): the controller partial
+// named by `path`, rendered on create (no record) and update (?id=). It holds
+// no value. The row's visible label, when declared, names the group. A form
+// without a controller (a settings page) has no partial route to call.
+const props = defineProps<FieldControlProps>()
+</script>
+
+<template>
+  <div
+    :id="controlId"
+    role="group"
+    data-partial-field
+    :aria-labelledby="props.field.label ? `${controlId}-label` : undefined"
+    :aria-describedby="describedBy || undefined"
+  >
+    <PartialHost
+      v-if="source"
+      variant="field"
+      :source="source"
+      :name="props.field.path || props.field.name"
+      :record-id="recordId ?? null"
+    />
+    <ExtensionFailure v-else data-partial-failed :text="t('backend::lang.extension.partial_failed')" />
+  </div>
+</template>

admin/src/components/form/fields/WidgetField.vue

@@ -162,7 +162,7 @@ onBeforeUnmount(() => {
     :id="controlId"
     role="group"
     data-widget-host
-    :aria-labelledby="`${controlId}-label`"
+    :aria-labelledby="field.label ? `${controlId}-label` : undefined"
     :aria-describedby="describedBy || undefined"
     :aria-busy="status === 'loading' ? 'true' : undefined"
     class="flex min-h-input items-center"

admin/src/components/form/registry.ts

@@ -4,12 +4,13 @@
 // is registered like any control but holds no form value: it edits its
 // relation through its own endpoints and renders only on an existing record.
 // Phase 10.1 adds the plugin extension types: a widget mounts a plugin custom
-// element (D-04, D-09). It holds no form value either, but it renders on
-// create and update.
+// element (D-04, D-09) and a partial renders a server template (D-17). They
+// hold no form value either, but they render on create and update.
 import type { Component } from 'vue'
 import CheckboxField from './fields/CheckboxField.vue'
 import DropdownField from './fields/DropdownField.vue'
 import NumberField from './fields/NumberField.vue'
+import PartialField from './fields/PartialField.vue'
 import RelationManager from '../relation/RelationManager.vue'
 import RelationField from './fields/RelationField.vue'
 import SwitchField from './fields/SwitchField.vue'
@@ -37,6 +38,7 @@ const renderers = new Map<string, Component>([
   ['relation', RelationField],
   [RELATION_MANAGER, RelationManager],
   ['widget', WidgetField],
+  ['partial', PartialField],
 ])
 
 /** Types whose control shows the label itself (toggle cards, relation manager). */
@@ -49,13 +51,13 @@ const selfLabelled = new Set<string>(['switch', 'checkbox', RELATION_MANAGER])
 const recordBound = new Set<string>([RELATION_MANAGER])
 
 /** Types that hold no form value: never part of the save body (D-09). */
-const valueless = new Set<string>([RELATION_MANAGER, 'widget'])
+const valueless = new Set<string>([RELATION_MANAGER, 'widget', 'partial'])
 
 /**
  * Types whose control is a group rather than one focusable element: the
  * visible label is a span the group points at, not a label for an input.
  */
-const groupLabelledTypes = new Set<string>(['widget'])
+const groupLabelledTypes = new Set<string>(['widget', 'partial'])
 
 export function rendererFor(type: string): Component {
   return renderers.get(type) ?? UnsupportedField
@@ -75,7 +77,10 @@ export function ownsLabel(type: string): boolean {
   return selfLabelled.has(type)
 }
 
-/** Whether a field type's label labels a group (widget) instead of a control. */
+/**
+ * Whether a field type's label names a group (widget, partial) instead of a
+ * control. Such a row shows no label row when the field declares no label.
+ */
 export function groupLabelled(type: string): boolean {
   return groupLabelledTypes.has(type)
 }