Fix/minor bug fixes

[sudhir9297]

What does this PR do?

This PR improves editor stability, undo/redo reliability, snapping consistency, and fence tooling, with a strong focus on smoother drag interactions and better performance during editing.

It introduces:

• A more robust undo/redo system that avoids noisy history and ensures clean state commits
• Improved snapping behavior across walls, fences, slabs, roofs, and stairs
• Full fence editing parity with walls, including curve support and endpoint controls
• Performance optimizations to prevent heavy recomputation during drag interactions
• Fixes for editor stability issues and interaction conflicts

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Undo & History

• Paused scene history during wall and fence move/curve tools to prevent drag previews from flooding undo stack.
• Fixed nested pause/resume conflicts caused by space detection re-enabling history mid-drag.
• Updated move commit flow:
  • Restore original baseline state
  • Apply final state as a single undoable action
• Improved undo/redo redraw timing so position updates reflect immediately.
• Added shared undo/redo helpers to:
  • Clear live transform states
  • Force dirty-node refresh after history jumps

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Wall & Fence Move / Snap

• Fixed wall endpoint dragging so constrained (horizontal/vertical/diagonal) moves respect snap targets.
• Updated fence endpoint tools to use:
  • Active grid step
  • Angle snapping (same as walls)
• Added snap-target following for:
  • Roofs
  • Stairs
  • Slabs
    → These now snap to wall/fence targets instead of only grid midpoints.
• Updated slab/ceiling hole editing to respect current grid snap settings via shared polygon editor.

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Fence Tooling

• Fixed fence move undo behavior to match wall behavior.
• Added fence endpoint move tools:
  • Linked endpoint movement
  • Alt + drag detach support
• Fixed endpoint action-button placement so handles appear correctly at fence ends.
• Added full curved fence support:
  • curveOffset added to schema
  • Curved fence geometry in renderer
  • Curve tool with live preview and single-step undo
  • Curve controls in fence panel and floating action menu
• Added snapping support for curved fence editing.

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Performance & Drag Responsiveness

• Disabled space detection during paused history to avoid expensive recomputation while dragging.
• Prevented room/slab/ceiling recalculation on every preview tick.
• Reduced render thrashing during wall drag operations.
• Kept move/curve previews smooth and real-time during interaction.

---

Floorplan & Editor Stability

• Fixed Maximum update depth exceeded loop in floorplan panel by preventing redundant viewport updates.
• Prevented floorplan and selection interactions from interfering during fence curve mode.

---

Slab / Ceiling Panel UX

• Added missing Actions section header in slab panel.
• Ensured Move action appears in the correct location for consistency.

[wass08]

Architectural review — PR #267 (editor)

Scope: 5 commits, 26 files, +1028/−128. Adds curved fence rendering, fence endpoint-move and curve tools, aligns roof/slab dragging to wall/fence snap targets, and introduces a ref-counted scene-history pause primitive in core.

Rules consulted: .claude/rules/systems.md, renderers.md, tools.md, viewer-isolation.md (mandatory four) plus spot-checks of the editor store for hook hygiene.

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Findings

Blockers

None.

Suggestions

S1. Space-detection gating is coupled to the history-pause counter — packages/core/src/lib/space-detection.ts:862

const unsubscribe = sceneStore.subscribe((state: any) => {
  if (isProcessing) return
  if (getSceneHistoryPauseDepth() > 0) return
  …

The skip is piggy-backing on the history-pause depth as a "tool is mid-interaction" signal. That semantics leaks beyond what history-control.ts claims to model. If any future caller pauses history for a non-tool reason (e.g. batching, import), space-detection will silently stop running — surprising and hard to debug.

Rule: .claude/rules/systems.md — systems should be driven by their own dirty signals, not indirectly by an unrelated concern.

Proposed fix: Introduce an explicit flag (e.g. useEditor.isInteracting, or a dedicated counter in the scene store like sceneInteractionDepth) that tool mounts toggle, and gate space-detection on that rather than getSceneHistoryPauseDepth(). Keep history-pause purely about history.

S2. snapFenceDraftPoint is now the shared snap helper, but it still lives under tools/fence/ — packages/editor/src/components/tools/roof/move-roof-tool.tsx:17 and packages/editor/src/components/tools/slab/move-slab-tool.tsx:18

import { snapFenceDraftPoint } from '../fence/fence-drafting'

Roof and slab move tools now reach into the fence tool's folder for their snap logic. Nothing in .claude/rules/tools.md forbids cross-tool imports, but the name and location imply fence-only ownership while two unrelated tools depend on it.

Proposed fix: Move the grid-point + wall/fence snap target helpers (snapFenceDraftPoint, findFenceSnapTarget, isWallLongEnough, grid-step helpers) into packages/editor/src/components/tools/shared/snap-helpers.ts (or packages/core/src/lib/snap.ts if stateless), and have fence/wall/slab/roof tools all import from there. Keeps the fence folder focused on fence-specific drafting state.

S3. refreshSceneAfterHistoryJump marks every node dirty on every undo/redo — packages/editor/src/lib/history.ts:5

function refreshSceneAfterHistoryJump() {
  useLiveTransforms.getState().clearAll()
  const state = useScene.getState()
  for (const node of Object.values(state.nodes)) {
    state.markDirty(node.id)
  }
}

The temporal subscriber in use-scene.ts already diffs prevNodesSnapshot → currentNodes and marks only the changed nodes. This synchronous pass on every keypress is O(nodes) and renders the diffing logic redundant — it just exists to paper over the fact that the diff runs in a queueMicrotask. On a large scene this will show up in the interaction frame.

Rule: .claude/rules/systems.md — avoid expensive per-interaction logic when a system (the temporal subscriber) already produces the correct derived state.

Proposed fix: Either rely on the microtask diff alone (now that it's no longer behind requestAnimationFrame, timing should be fine), or if there's a specific render that needs a synchronous flush, mark only the nodes that moved via live transforms (useLiveTransforms.getState().keys()) before clearing — not every node.

Nits

N1. Duplicated world-coord branch in FloatingActionMenu — packages/editor/src/components/editor/floating-action-menu.tsx:135-163

The wall-vs-fence endpoint world-position computation has the node.type === 'wall' ? … : … ternary twice with nearly identical shape. Extracting a tiny getEndpointWorldPoint(obj, segment, which: 'start' | 'end') helper would be clearer and remove the embedded Math.hypot call. Not a rule issue; optional.

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Summary

• Blockers: 0
• Suggestions: 3
• Nits: 1

Verdict: ready to merge (with the three suggestions worth a follow-up thread).

The PR respects the layer boundaries that matter most: packages/viewer/** is untouched, the new history-control primitive sits correctly in core and exposes a pure TS API, new editor-only state (movingFenceEndpoint, curvingFence) lives in useEditor rather than useViewer, and all new tools are in packages/editor/src/components/tools/fence/ and wired through ToolManager. The fence-curve rendering work in FenceSystem reuses the existing wall-curve helpers cleanly and doesn't duplicate geometry math. Selector additions are value subscriptions, not reference-generating slices.