feat(core): declarative world-space objects + editor bridge object commands

[hblee12294]

objects?: ObjectConfig[] — engine-managed 3D props in the main scene, the world-space sibling of elements[].

The capability

"objects": [
  { "id": "p0",
    "asset": { "kind": "primitive", "shape": "knot", "color": "#ffb03a" },
    "transform": { "x": 1, "y": 0.5, "z": -2, "ry": 40, "scale": 0.6 } },
  { "id": "m0", "asset": { "kind": "gltf", "key": "https://…/model.glb" } }
]

• Assets: parametric primitives (cube | sphere | torus | knot; standard material with color/metalness/roughness, or unlit: true for a light-free basic material) and GLB models by URL — bbox-normalized at load so transform.scale is asset-independent, with per-instance cloned materials. A gltf asset auto-detects the GLTFLoader addon (objects are data — function-string keyword scanning can't see them).
• Transforms are raw world units; apps map their own layout conventions onto world units before authoring the config.
• Each object is an ObjectInstance { config, root, props, dispose } in an id-keyed Map exposed as ctx.objects and on the result. The props bag is the single animatable/editable surface — the render loop mirrors it onto the mesh every frame, so tweens targeting ctx.objects.get(id).props and editor overrides compose exactly like element props.
• Lighting is the author's choice: standard materials expect lights from createContent; unlit renders without any.

Bridge (protocol 2 → 3)

• SET_OBJECT_PROPS { id, props } — ephemeral overrides for gesture-time preview; cleared by LOAD (durable state stays in the config).
• OBJECT_HIT_TEST { x, y, requestId } → OBJECT_HIT_RESULT { requestId, id | null } — a main-camera raycast; nearest hit wins (real 3D depth, unlike overlay elements), child hits walk up to the registered root.

Compatibility

Fully additive: configs without objects compile byte-identically (pinned by test); no config version bump. 135 tests pass (7 new: codegen, unlit, GLTFLoader auto-detect + non-detect, context/result exposure, editor/non-editor bridge surface). Changeset: minor.

[hblee12294]

Real-browser verification (headless Chrome against the built package — compiled config booted through the editor render template):

• ✅ lit knot / unlit cube / GLB duck all render (pixel checks at their screen positions; background clean)
• ✅ OBJECT_HIT_TEST returns the right id for each — including GLB child-mesh hits walking up to the registered root
• ✅ empty space returns null
• ✅ SET_OBJECT_PROPS moves an object: the old position stops hitting, the new one hits

This pass caught one real bug the unit tests couldn't: the editor api raycasts with __current.camera, but the result only exposed overlayCamera — every object hit-test returned null while rendering worked. Fixed in ce557fd (camera now rides the result's introspection handles, pinned by test).