3D nodes: "camera lock toggle" reported missing — control does not exist in FE (needs QA clarification)

## QA finding (1.47 RC re-test, P2)

> Camera lock toggle is not displayed on 3D nodes.

## Investigation

A "camera lock" / lock-camera / freeze-orbit toggle **does not exist** anywhere in the frontend, so this is not a regression on the release branch:

- No `lockCamera` / `lockView` / `toggleLock` / `camera lock` string in `src/` (only unrelated `Clock`, `Canvas ToggleLock`, `lock aspect ratio`).
- The camera controls on 3D nodes are only: **camera-type switch** (perspective↔orthographic) and **FOV**, plus top-level **fit-to-viewer** and **center-camera** buttons. See `src/components/load3d/controls/CameraControls.vue`, `src/components/load3d/menubar/CameraMenuGroup.vue`, `src/components/load3d/Load3DMenuBar.vue`.
- `ControlsManager.detach()/attach()` can flip `OrbitControls.enabled` (`src/extensions/core/load3d/ControlsManager.ts`) but is **not wired to any UI toggle** (only used for the external-camera path / tests).
- No commit in history reachable from `main` ever introduced a camera lock/record toggle.
- The official Load3D docs (docs.comfy.org/built-in-nodes/Load3D) document only the camera-type toggle and FOV — no lock.

### Most likely explanation

The nearest recently-added camera toggle is the **"use custom up / use natural up"** button (compass / rotate icon next to camera-switch), added by commit `5ab07570c` *"feat(camera-info): 3D viewport widget for CreateCameraInfo node"*. That commit lives **only on the unmerged branch `origin/feat/create-camera-info-preview`** and is not on `main` / the release branch. A build containing that branch would show an extra camera toggle that is legitimately absent from the RC.

## Ask

@QA — please confirm which control you expected and which build/branch you saw it on:
1. Is "camera lock" the **use-custom-up toggle** from `feat/create-camera-info-preview` (i.e. that feature just isn't merged into 1.47 yet)? → this is a merge/backport scheduling question, not a bug.
2. Or is an **actual orbit-lock button** (freeze the camera) a genuinely-requested new feature? → that is unbuilt; it would be a new toggle in `CameraControls.vue`/`CameraMenuGroup.vue` wired through `useLoad3d.ts` to `ControlsManager.attach()/detach()`.

No FE code change is being made until the expected control is confirmed, to avoid shipping an unreviewed/in-progress feature under a bugfix.