editor: keep room surfaces in sync with wall topology

[sudhir9297]

What does this PR do?

Keeps room walls, generated slabs, and generated ceilings aligned as wall topology changes.

Wall topology

• Splits straight and curved walls when a divider connects to or crosses them.
• Splits crossing dividers so all wall segments meet at the same junction.
• Preserves doors, windows, and wall-mounted items on the correct replacement wall.
• Applies each multi-wall operation atomically as one undo step.
• Avoids duplicate/covered walls, near-endpoint slivers, and invalid splits through openings.

Slabs and ceilings

• Creates one generated slab and ceiling per detected room after a divider is added.
• Updates or merges surfaces when dividers move or are removed.
• Preserves materials, slots, dimensions, visibility, heights, and openings when rooms split.
• Combines compatible surfaces and preserves conflicting customized surfaces as manual surfaces.
• Keeps deliberately deleted generated surfaces deleted after later edits or reloads.
• Keeps existing slabs and ceilings when an exterior wall is removed.

Scoped reconciliation

• Uses an in-memory topology index to reconcile only rooms near the changed walls.
• Does not persist deletion-memory or topology-index data in project files.
• Does not generate missing surfaces merely because an existing project was loaded.
• Rebuilds the in-memory index safely after load, undo, and redo.

Editor behavior

• Keeps 2D and 3D wall-chain continuation consistent.
• Keeps a 2D wall chain active when a duplicate or covered commit is rejected.
• Moves topology planning into @pascal-app/core; editor tools only apply the resulting atomic scene changes.

How to test

1. Run bun run check, bun run lint, and bun run check-types.
2. Create a four-wall room and confirm it has one slab and one ceiling.
3. Add a divider and confirm both boundary walls split and the tree shows two slabs and two ceilings.
4. Cross two dividers and confirm four wall segments meet at the center and four room surfaces are generated.
5. Connect a divider to a curved wall and confirm the curve and any hosted openings remain correct.
6. Customize surfaces, then split and merge rooms; confirm materials, dimensions, and openings are preserved.
7. Delete a generated slab or ceiling, edit another wall, and reload; confirm the deleted surface remains absent.
8. Remove an exterior wall and confirm its existing slab and ceiling remain unchanged.

Validation

• Full source suite: 2,227 passed, 1 skipped, 0 failed.
• bun run check, bun run lint, and bun run check-types pass.

Checklist

• Tested locally
• Follows existing code style
• Targets main

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Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

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Index treats new walls as stale

Medium Severity

sameIndexedWall compares missing walls with left === right, but the cache lookup returns undefined while the before-state path normalizes absence to null. For any newly created wall ID, that mismatch makes ensureBeforeLevel discard the spatial index and rebuild the whole level, so divider inserts take the fallback path instead of the indexed reconcile the PR is built around.

Additional Locations (1)

• packages/core/src/lib/space-detection.ts#L1901-L1916

 

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