feat(12.1-01): declared bulk actions on admin lists

- pact.HasAdminBulkActions with AdminBulkAction, its input and result
- config_list.yaml bulkActions, compiled fail-loud, needs showCheckboxes
- POST .../{controller}/bulk/{action}: ids resolved and locked through the
  list scope in one transaction; partial selection is 409
- list schema offers declared actions per principal, with confirm text
- admin SPA bulk actions menu with confirm, busy state and failure toasts
- acme.roster fixture, tracer test, OpenAPI, TS types, dist, READMEs, docs

admin/src/components/list/BulkActionsMenu.vue

@@ -0,0 +1,60 @@
+<script setup lang="ts">
+import { ref } from 'vue'
+import { DropdownMenuContent, DropdownMenuItem, DropdownMenuPortal, DropdownMenuRoot, DropdownMenuTrigger } from 'reka-ui'
+import { ChevronDown } from '@lucide/vue'
+import type { BulkAction } from '../../api/types'
+import { t } from '../../app/i18n'
+import Button from '../ui/Button.vue'
+
+// Bulk actions menu (UI-SPEC S1, D-09): the declared bulk actions the server
+// already filtered to what the admin may run, in declared order. The built-in
+// delete is not listed here; it stays the toolbar button. Labels come from
+// the server and are rendered as text. The trigger keeps its label while
+// disabled (nothing selected, or an action running).
+defineProps<{
+  actions: BulkAction[]
+  disabled: boolean
+}>()
+const emit = defineEmits<{ select: [name: string] }>()
+
+const trigger = ref<InstanceType<typeof Button> | null>(null)
+
+/** Moves focus back to the trigger after the confirmation closes. */
+function focus(): void {
+  const el = trigger.value?.$el
+  if (el instanceof HTMLElement) {
+    el.focus()
+  }
+}
+
+defineExpose({ focus })
+</script>
+
+<template>
+  <DropdownMenuRoot :modal="false">
+    <DropdownMenuTrigger as-child :disabled="disabled">
+      <Button ref="trigger" variant="outline" size="md" data-action="bulk-actions" :disabled="disabled">
+        {{ t('backend::lang.list.bulk_actions') }}
+        <ChevronDown :size="16" class="text-muted" aria-hidden="true" />
+      </Button>
+    </DropdownMenuTrigger>
+    <DropdownMenuPortal>
+      <DropdownMenuContent
+        data-bulk-menu
+        align="end"
+        :side-offset="8"
+        class="z-50 flex w-[240px] max-w-[320px] flex-col rounded-[14px] border border-border bg-surface p-2 text-text shadow-menu"
+      >
+        <DropdownMenuItem
+          v-for="action in actions"
+          :key="action.name"
+          :data-bulk-action="action.name"
+          class="flex min-h-10 cursor-pointer items-center rounded-control px-3 py-2 outline-none transition-colors duration-150 ease-out data-[highlighted]:bg-hover"
+          @select="emit('select', action.name)"
+        >
+          {{ action.label }}
+        </DropdownMenuItem>
+      </DropdownMenuContent>
+    </DropdownMenuPortal>
+  </DropdownMenuRoot>
+</template>

admin/src/components/list/ListToolbar.vue

@@ -1,9 +1,10 @@
 <script setup lang="ts">
-import { computed } from 'vue'
+import { computed, ref } from 'vue'
 import { Check, Search, Trash2 } from '@lucide/vue'
-import type { ToolbarAction } from '../../api/types'
+import type { BulkAction, ToolbarAction } from '../../api/types'
 import { t } from '../../app/i18n'
 import Button from '../ui/Button.vue'
+import BulkActionsMenu from './BulkActionsMenu.vue'
 
 // List toolbar (design screen 3, D-14): the search input and the toolbar
 // buttons in declared order. Delete is a disabled outline button without a
@@ -11,6 +12,9 @@ import Button from '../ui/Button.vue'
 // A registered plugin action (D-12) is an outline button labelled from
 // `actions`, the list the server already filtered to what the admin may run;
 // it ignores the selection and is disabled and busy while its POST runs.
+// Declared bulk actions (D-09) sit in one menu directly after the selection
+// pill; the menu is not rendered without a permitted action, and its trigger
+// is disabled while nothing is selected or a bulk action runs.
 const props = withDefaults(
   defineProps<{
     showSearch: boolean
@@ -22,12 +26,23 @@ const props = withDefaults(
     deleteLabel: string
     actions?: ToolbarAction[]
     busyAction?: string | null
+    bulkActions?: BulkAction[]
+    bulkBusy?: boolean
   }>(),
-  { actions: () => [], busyAction: null },
+  { actions: () => [], busyAction: null, bulkActions: () => [], bulkBusy: false },
 )
-const emit = defineEmits<{ 'update:search': [value: string]; delete: []; action: [name: string] }>()
+const emit = defineEmits<{ 'update:search': [value: string]; delete: []; action: [name: string]; bulk: [name: string] }>()
 
 const labels = computed(() => new Map(props.actions.map((action) => [action.name, action.label])))
+
+const bulkMenu = ref<InstanceType<typeof BulkActionsMenu> | null>(null)
+
+/** Moves focus to the bulk menu trigger (after its confirmation closes). */
+function focusBulk(): void {
+  bulkMenu.value?.focus()
+}
+
+defineExpose({ focusBulk })
 </script>
 
 <template>
@@ -45,7 +60,7 @@ const labels = computed(() => new Map(props.actions.map((action) => [action.name
       />
     </label>
     <span v-else />
-    <div class="flex items-center gap-2.5">
+    <div class="flex flex-wrap items-center justify-end gap-2.5">
       <span
         v-if="selectedCount > 0"
         data-selected-pill
@@ -53,6 +68,13 @@ const labels = computed(() => new Map(props.actions.map((action) => [action.name
       >
         <Check :size="14" aria-hidden="true" />{{ selectedLabel }}
       </span>
+      <BulkActionsMenu
+        v-if="bulkActions.length > 0"
+        ref="bulkMenu"
+        :actions="bulkActions"
+        :disabled="selectedCount === 0 || bulkBusy"
+        @select="(name: string) => emit('bulk', name)"
+      />
       <template v-for="button in buttons" :key="button">
         <Button
           v-if="button === 'delete'"