feat(studio): add organize-imports tool with suggestion review and approval

Adds a Studio 'Organize imports' dialog that groups recently imported
furniture and furniture already sitting in the auto-created import
pages into suggested catalog categories.  Each group is presented with
its suggested name, icon, and layout which can be overridden before
approval; approved groups are turned into real catalog pages in a
single atomic export run.  Offers already inside the import subtree are
moved to the new pages; brand-new furniture gets a fresh offer.

- groupSuggestedCategories: generic pure helper reusing the same
  per-item label heuristic that drives suggestCategoryName; items with
  no label land in a 'Other Furni' remainder bucket
- GET /api/admin/import/organize: returns items from the imported
  furniture tree (catalog_items JOIN items_base via page id set from
  the imported-furniture root) union audit-logged but not-yet-placed
  recent imports; marks alreadyPlaced vs new
- organizeImportFurni server action: validates import-page membership
  before moving any offer, creates pages + inserts/moves items in one
  withCatalogExport snapshot, logs activity
- OrganizeImportsDialog: full-featured Studio dialog with price panel
  (applies to new offers only), parent select, per-group approval,
  editable name/icon/layout with suggestion reset chips, source tags
- import-pages.ts server helper: locates the imported-furniture tree
- Studio nav: 'Organize imports' button with FolderTree icon,
  gated on CATALOG_EDIT, wired next to the catalog manager
- en + nl translations for organizeImports.* keys with ICU plurals
- groupSuggestedCategories unit tests (deterministic grouping,
  remainder handling, size+alpha ordering, label consistency)

src/messages/en.json

@@ -2198,6 +2198,36 @@
 						"cancel": "Cancel",
 						"create": "Create",
 						"createWithItems": "Create ({count} items)"
+					},
+					"organizeImports": {
+						"title": "Organize imports",
+						"itemsBadge": "{count} items",
+						"loading": "Loading imported furniture…",
+						"empty": "No imported furniture found. Import furniture first.",
+						"refresh": "Refresh",
+						"desc": "Imported furniture is grouped into suggested pages. Review each group, then create the pages you approve.",
+						"selectAll": "Select all",
+						"deselectAll": "Deselect all",
+						"name": "Name",
+						"icon": "Icon",
+						"layout": "Layout",
+						"resetSuggestion": "Suggested",
+						"suggestedLayout": "Suggested: {layout}",
+						"movedLabel": "{count} moved",
+						"newLabel": "{count} new",
+						"isNew": "new",
+						"price": "Price",
+						"free": "Free",
+						"setPrice": "Set a price",
+						"credits": "Credits",
+						"points": "Points",
+						"pointsType": "Type",
+						"newPriceHint": "Applies to new offers only; moved offers keep their current price.",
+						"parent": "Place pages under",
+						"root": "Catalog root",
+						"importedRoot": "Imported Furniture",
+						"cancel": "Cancel",
+						"create": "Create {count, plural, one {1 page} other {# pages}}"
 					}
 				},
 				"bulk": {