feat(gallery): add admin gallery curation endpoints and management page (Task 6)

Add super-admin-only backend endpoints for toggling is_gallery_featured and
gallery_sort_order on flows and scripts, plus a frontend GalleryManagementPage
with toggle switches, editable sort order fields, and name/featured filters.
13 integration tests; all pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/api/admin.ts

@@ -50,6 +50,23 @@ export interface SurveyResponseListResponse {
   unread: number
 }
 
+export interface GalleryFlowItem {
+  id: string
+  name: string
+  tree_type: string
+  is_gallery_featured: boolean
+  gallery_sort_order: number
+  visibility: string
+}
+
+export interface GalleryScriptItem {
+  id: string
+  name: string
+  is_gallery_featured: boolean
+  gallery_sort_order: number
+  is_active: boolean
+}
+
 export const adminApi = {
   // Dashboard
   getDashboardMetrics: () =>
@@ -194,6 +211,20 @@ export const adminApi = {
     api.delete(`/admin/survey-responses/${id}`),
   bulkActionResponses: (action: string, ids: string[]) =>
     api.post('/admin/survey-responses/bulk', { action, ids }).then(r => r.data),
+
+  // Gallery Curation
+  getGalleryFeatured: () =>
+    api.get<{ flows: GalleryFlowItem[]; scripts: GalleryScriptItem[] }>('/admin/gallery/featured').then(r => r.data),
+  getGalleryAllItems: () =>
+    api.get<{ flows: GalleryFlowItem[]; scripts: GalleryScriptItem[] }>('/admin/gallery/items').then(r => r.data),
+  toggleFlowFeatured: (id: string, is_gallery_featured: boolean) =>
+    api.patch<GalleryFlowItem>(`/admin/gallery/flows/${id}/feature`, { is_gallery_featured }).then(r => r.data),
+  updateFlowSortOrder: (id: string, gallery_sort_order: number) =>
+    api.patch<GalleryFlowItem>(`/admin/gallery/flows/${id}/sort-order`, { gallery_sort_order }).then(r => r.data),
+  toggleScriptFeatured: (id: string, is_gallery_featured: boolean) =>
+    api.patch<GalleryScriptItem>(`/admin/gallery/scripts/${id}/feature`, { is_gallery_featured }).then(r => r.data),
+  updateScriptSortOrder: (id: string, gallery_sort_order: number) =>
+    api.patch<GalleryScriptItem>(`/admin/gallery/scripts/${id}/sort-order`, { gallery_sort_order }).then(r => r.data),
 }
 
 export default adminApi