editor: add Blender-style custom mesh editing

[sudhir9297]

What does this PR do?

• Adds a registry-driven Custom Mesh node with 3D placement, floor-plan rendering, paint support, and Blender-style vertex, edge, and face editing.
• Adds mesh transforms and topology operations including extrude, inset, bevel, loop cut, merge, dissolve, and delete, with an interaction-scoped floating toolbar and keyboard controls.
• Supports elevated and registry-declared top surfaces for stairs and other floor-placed nodes, including plugin-defined surfaces and Alt force placement without hardcoded node-kind dispatch.
• Refines the edit/selection menus, removes the obstructive secondary help strip, and documents the interaction-scope and custom-mesh design.

How to test

1. Run bun dev, open the editor, choose Custom Mesh from the build palette, and place it on the ground and on an elevated top surface; verify the preview follows the pointed surface and commits without an error overlay.
2. During Custom Mesh placement, hold Alt over an otherwise invalid or overlapping position; verify snapping is bypassed and the mesh can be force-placed.
3. Select a Custom Mesh, choose Edit mesh, switch between vertex/edge/face selection, and exercise translate, rotate, scale, extrude, inset, bevel, loop cut, merge, dissolve, and delete; verify Tab or the check button exits edit mode.
4. Place or move a stair over a Custom Mesh/elevated surface and verify a single click commits it at that elevation without the floating helper blocking the pointer.
5. Run bun run check, bun run check-types, and bun run build.

Screenshots / screen recording

A short screen recording will be added before review. The interactive placement and helper UI were smoke-tested in the local collaborative preview.

Checklist

• I've tested this locally with bun dev
• My code follows the existing code style (run bun check to verify)
• I've updated relevant documentation (if applicable)
• This PR targets the main branch

---

Note

High Risk
Touches core spatial-grid support election, item placement/commit, and scene load migration for a new structural node type—regressions could affect elevation, hosting, and saved scenes.

Overview
Renames and migrates legacy custom-mesh scenes to block: new topology schema, level children, item blockFaceId, BlockEvent, and generic node:* bus events alongside per-kind events.

Adds registry faceHost so blocks (and other kinds) can host wall, ceiling, and floor items on planar faces, with a dedicated placement strategy, preview/commit paths, sloped-face rules, and grid/oriented-surface snapping.

Floor support gains pinSupport, preferred-slab resolution, resolveFrozenFloorPlacementPatch (exact elevation on mesh tops without live hosting edges), and shared wall/fence construction helpers so later slabs do not lift pinned placements; fence drafting and item/move commits thread pointer caps and pinning through resolveSupportSlabPatch.

Editor UX: Edit mesh on the action menu, mesh-editing scope disables normal selection/hover, build tab waits for client registry via useSyncExternalStore, and move/placement tools consolidate commits on node:click with frozen support on pointed construction surfaces.

getTopSurfaceHeight now receives the full node map for context-aware host surfaces.

^{Reviewed by Cursor Bugbot for commit 0d96de0. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Deleted faces orphan hosted items

Medium Severity

Face delete/dissolve/merge can remove a face while items still reference it via customMeshFaceId. CustomMeshFaceHostFrame then fails to resolve a frame and renders those children without the face transform, so hosted items jump to incorrect local coordinates instead of being cleaned up or reparented.

Additional Locations (1)

• packages/nodes/src/custom-mesh/commands.ts#L1019-L1061

 

^{Reviewed by Cursor Bugbot for commit 63c131e. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 2 potential issues.

There are 3 total unresolved issues (including 1 from previous review).

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit f5e30df. Configure here.}

[cursor]

Stale face-host live overrides

High Severity

commitDraft clears live overrides only after draftNode.commit(), when draftNode.current is already null, so faceHostClearFields falls back to position/rotation and skips blockFaceId. Face-host moves write blockFaceId into useLiveNodeOverrides, and wall-side / ceiling items can leave a block without the leave path clearing those overrides. getEffectiveNode can then keep reapplying a stale blockFaceId after a successful wall or ceiling commit.

Additional Locations (2)

• packages/editor/src/components/tools/item/use-placement-coordinator.tsx#L1592-L1602
• packages/nodes/src/block/face-host.ts#L186-L189

 

^{Reviewed by Cursor Bugbot for commit f5e30df. Configure here.}

[cursor]

Ceiling enter keeps block face

Medium Severity

Ceiling enter and click update parentId and position but never clear blockFaceId or blockId, unlike wall and roof-wall transitions. Ceiling items can move from a block underside onto a real ceiling without going through face-host leave, so the draft can stay marked as block-hosted while parented to a ceiling.

Additional Locations (2)

• packages/editor/src/components/tools/item/placement-strategies.ts#L849-L856
• packages/editor/src/components/tools/item/placement-strategies.ts#L271-L286

 

^{Reviewed by Cursor Bugbot for commit f5e30df. Configure here.}