catalog: extract pure helpers + 34 cases, consume them from useCatalog

First half of the proposed `useCatalog` decomposition. The 1036-line
god-hook still owns the singleton-via-useBetween, but the pure logic
it used to define inline now lives in a dependency-free module so it
can be tested in isolation and reused by future split-out hooks
(`useCatalogData` / `useCatalogUiState` / `useCatalogActions` when
those land).

New module: `src/hooks/catalog/useCatalog.helpers.ts` (222 LOC).

- `normalizeCatalogType(type?)` — coerce the optional catalog type to
  `NORMAL` / `BUILDER`. Was a 5-line `useCallback` with an empty
  dependency array.
- `getOfferProductKeys(offer)` — produces the canonical
  `productType:id:classId` and `productType:class:className` keys
  for the resolved-offer cache.
- `findNodeById` / `findNodeByName` — DFS over the catalog tree,
  root explicitly excluded so callers can't select the synthetic
  root by mistake.
- `getNodesByOfferIdFromMap(offerId, map, onlyVisible)` — extracted
  from the closed-over `getNodesByOfferId`. The `onlyVisible`
  fallback to the full bucket when nothing visible remains is
  preserved.
- `buildCatalogNodeTree(NodeData)` — pulled out of the
  `CatalogPagesListEvent` reducer. Builds the tree and the offerId
  index in one pass; the caller now does `const { rootNode,
  offersToNodes } = buildCatalogNodeTree(parser.root)` instead of
  carrying an inline recursive walker + a local map.
- `resolveBuilderFurniPlaceableStatus(input)` — the placement
  decision tree as a pure function. The hook keeps the
  `GetRoomEngine` / `GetSessionDataManager` reads that count
  non-self, non-moderator visitors (only when the subscription has
  expired) and forwards the resulting `visitorCount` into the
  helper, so the previous early-exit semantics are preserved.

`useCatalog.ts` now imports these and removes ~140 lines of inline
copies. Net hook size: 1036 → 961 LOC. Behavior unchanged.

Tests: `tests/useCatalog.helpers.test.ts` (34 cases).

- `normalizeCatalogType` (4) — BUILDER pass-through, NORMAL
  pass-through, undefined/empty fallback, unknown string fallback.
- `getOfferProductKeys` (5) — both keys, id-only when classId<0,
  class-only when className empty, no-product short-circuit,
  empty productType short-circuit.
- `findNodeById` (5) — null input, root exclusion, immediate child,
  grandchild, miss returns null.
- `findNodeByName` (2) — match by name + root exclusion, miss.
- `getNodesByOfferIdFromMap` (5) — empty map, raw bucket pass-through,
  visible-only filter, fallback when no visible remain, miss.
- `buildCatalogNodeTree` (3) — root depth=0 + empty offer map for a
  leaf-only root, DFS traversal tracks offer→nodes across branch
  and leaf, child.parent === root.
- `resolveBuilderFurniPlaceableStatus` (10) — missing offer,
  not-in-room, owner happy path, non-owner without fallback,
  guild admin with time, furni limit reached, shared-pool override
  ignoring the limit, expired+blocked-by-visitors flag,
  expired+visitor count > 0, expired+empty room is okay.

To support the placement-status test the renderer mock gains real
numeric values for `RoomControllerLevel` (NONE..MODERATOR) and
`RoomObjectCategory` (MINIMUM..MAXIMUM); the previous string-keyed
Proxy stubs made `controllerLevel >= GUILD_ADMIN` evaluate to NaN.

Suite: 158/158 (was 124/124). `yarn typecheck` green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -261,13 +261,13 @@ into `configurePreviewServer` so `yarn preview` keeps working.
 | God-hook split (state + actions + shim) | `doorbell`, `poll`, `furni-chooser`, `user-chooser`, `friend-request`, `chat-input` |
 | God-hook split (`useBetween` singleton + state filter + actions filter + shim) | `wired-tools`, `translation`, `notification`, `friends` |
 | `WidgetErrorBoundary` | `RoomWidgetsView` umbrella |
-| Vitest | 124/124 cases — 113 on pure helpers + Zustand store, plus the first 2 component-/hook-level pilots (WidgetErrorBoundary, useDoorbellState) on top of the new renderer-SDK mock at `tests/mocks/renderer-mock.ts` |
+| Vitest | 158/158 cases — pure helpers + Zustand store + 2 component-/hook-level pilots (WidgetErrorBoundary, useDoorbellState) on top of the renderer-SDK mock at `tests/mocks/renderer-mock.ts`, plus 34 cases on the freshly extracted catalog helpers |
 | Form Actions | Login / Register / Forgot (LoginView.tsx) |
 | Cherry-picked from `duckietm` PR #126 | `UserAccountSettingsView` (reset password / email / username under user settings), plus the wear-badge popup `canShowWearButton` gating |
 
 | Not yet | Notes |
 |---|---|
-| Core `useCatalog` split | Session-stable secondary fetches all migrated to TanStack queries (see ARCHITECTURE.md). What's left: core `rootNode`/`offersToNodes`/`currentPage` slice + Builders Club status. Needs a dedicated `useCatalogData`/`useCatalogUiState`/`useCatalogActions` split. |
+| Singleton-filter split of `useCatalog` | Pure helpers extracted to `useCatalog.helpers.ts` and consumed in the hook (`buildCatalogNodeTree`, `findNodeById`, `findNodeByName`, `getNodesByOfferIdFromMap`, `getOfferProductKeys`, `normalizeCatalogType`, `resolveBuilderFurniPlaceableStatus`). What still remains: split the singleton state into `useCatalogData` / `useCatalogUiState` / `useCatalogActions` filters via `useBetween`, mirroring the wired-tools / translation / notification / friends pattern. The 48 consumers can stay on the shim during the transition. |
 | Split `useChatWidget` / `useAvatarInfoWidget` | Both state-driven via events with no clean imperative actions to extract — skip-motivated. Already touched today for the InfoStand listener move. |
 | Split `usePetPackageWidget` / `useWordQuizWidget` / `useChatCommandSelector` | Their "actions" mutate internal state or are tightly interdependent — skip-motivated. |
 | Hoist Wired Creator Tools shared state to a Zustand slice | Would remove ~25 props passed to the 3 tab sub-components. (Wired-tools split done as singleton-filter; Zustand slice is the next step.) |
@@ -323,6 +323,10 @@ Fix shapes documented; both are reasonable PRs on their own.
 - Asset middleware: `nitroAssetsServer()` in `vite.config.mjs`
 - Configuration pre-init: `src/bootstrap.ts` (`await GetConfiguration().init()`
   before `import('./index')`)
+- Catalog pure helpers: `src/hooks/catalog/useCatalog.helpers.ts`
+  (`buildCatalogNodeTree`, `findNodeById` / `findNodeByName`,
+  `getNodesByOfferIdFromMap`, `getOfferProductKeys`,
+  `normalizeCatalogType`, `resolveBuilderFurniPlaceableStatus`)
 - Renderer-SDK mock for Vitest: `tests/mocks/renderer-mock.ts`
   (aliased over `@nitrots/nitro-renderer` via `vitest.config.mts`).
   Hosts the explicit `NitroLogger` mock, the `mockEventDispatcher` /