fix(nodes/wall): let a hovered wall out of its batch so it can outline

[wass08]

Hovering a wall on a finished floor lights up nothing — no hover outline in select mode, and in paint mode no preview of the surface the next click will paint. Selection looks fine, which is what makes it confusing.

Why

Hover feedback for a wall is an outline and nothing else. SelectionMaterialSync skips walls outright, and the cutaway pass tints only a selection or a delete hover — so default, paint-ready and paint-disabled all reduce to outliner.hoveredObjects plus a colour.

MergedOutlineNode draws that mask with renderer.render(scene, camera) on the main camera, which enables no BATCHED_LAYER. Once #608 sews a level's walls (wall mode up, 8+ walls, 180ms quiet) every wall on the floor is on that layer alone, so it reaches neither the depth pass nor a mask pass.

Selection escapes this only because collectTintedWalls already pulls a selected wall back out of the batch: the click lands, the wall starts drawing itself, and the outline appears. Hover had no such release.

Worth noting for anyone tracing this from #686: wall picking was never affected. The pointer handlers live on the collision-mesh child, which batching never moves off SCENE_LAYER, and R3F raycasts each interaction object directly — so clicks always landed. Only the feedback was missing.

Fix

Release on any hover, not just a delete one. Same mechanism, one more reason: selection and delete tint through materials the merged mesh never reads, a plain hover outlines through a camera that never sees it, and both are answered by the wall drawing its own geometry while it is lit. One wall is lit at a time, so the cost is the one extra draw call the delete path already accepted.

Verification

12-wall single-level project in the community editor, headless Chromium against a local dev server:

Wall mode	hover outline before	after
Full height (batching on)	none	outlines, select + paint + erase
Cutaway (batching stands down)	outlines	unchanged

bun test src in packages/nodes: 1052 pass. Regression test added over collectTintedWalls for all four hover modes.

🤖 Generated with Claude Code

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Note

Low Risk
Small, localized change to wall batch exclusion logic with regression tests; no auth, data, or API impact.

Overview
Fixes missing hover outlines on batched walls when wall mode is up and a level’s walls are merged into the batch mesh.

collectTintedWalls now treats any hovered wall ID like a lit wall (not only delete-mode hovers), so the batch system releases that wall to draw its own geometry again. That matches how selection already worked and is required for default/paint hovers, where feedback is an outline rendered through the main camera—which does not see walls on the batched layer.

The function is exported for tests. New regression tests cover all four hoverHighlightMode values plus hovers on non-wall nodes (no release).

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