fix(tools): support contour segmentation undo and redo

[sedghi]

Summary

• preserve contour-segmentation state across undo/redo after boolean stroke processing replaces the source annotation
• add Undo/Redo controls and standard keyboard shortcuts to the planar freehand contour segmentation example
• add HistoryMemo unit coverage and a browser-state regression for contour merge → undo → redo
• update the GenericViewport test harness to use the current RenderBackends enum name

Root cause

The planar freehand tool initially records an annotation-creation memo for the source stroke. Contour boolean processing then removes that source annotation and rebuilds the resulting contour annotations, leaving the memo pointed at an annotation that no longer exists. Undo therefore could not remove the committed contour, and redo could restore the obsolete source stroke.

This change replaces that provisional memo in-place with a memo that swaps the complete pre-stroke and post-stroke annotation sets, preserving a single undo step for creation, merges, and holes.

Validation

• corepack pnpm run test:vitest:browser tests/vitest-browser/undoRedoHistory.browser.test.ts — 9 passed, 1 expected failure
• corepack pnpm exec jest packages/core/test/utilities/historyMemo.jest.js --runInBand — 5 passed
• corepack pnpm exec tsc --project packages/core/tsconfig.json
• corepack pnpm exec tsc --project packages/tools/tsconfig.json
• Prettier, oxlint, and git diff --check

Summary by CodeRabbit

• New Features

  • Added support for replacing the current history entry while preserving undo/redo position.
  • Added undo and redo controls to the planar freehand contour segmentation example.
  • Added keyboard shortcuts: Ctrl/Cmd+Z for undo and Ctrl/Cmd+Y or Ctrl/Cmd+Shift+Z for redo.
  • Contour merge and editing actions now support reliable undo and redo restoration.

• Bug Fixes

  • Improved history handling for grouped contour edits and restored annotations.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 4a339f37-1e6d-47ec-b027-9f7dca548551

📥 Commits

Reviewing files that changed from the base of the PR and between a0bb6c5 and a1866db.

📒 Files selected for processing (7)

• packages/core/src/utilities/historyMemo/index.ts
• packages/core/test/utilities/historyMemo.jest.js
• packages/tools/examples/planarFreehandContourSegmentationTool/index.ts
• packages/tools/src/utilities/contourSegmentation/applyContourStroke.ts
• tests/vitest-browser/harness/createPlanarViewport.ts
• tests/vitest-browser/harness/tools.ts
• tests/vitest-browser/undoRedoHistory.browser.test.ts

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📝 Walkthrough

Walkthrough

Adds HistoryMemo.replaceCurrentMemo, integrates contour stroke merging with undo/redo annotation restoration, updates the planar contour example with controls and shortcuts, and adds browser test coverage and gesture support.

Changes

Contour history

Layer / File(s)	Summary
Current memo replacement packages/core/src/utilities/historyMemo/index.ts, packages/core/test/utilities/historyMemo.jest.js	Adds replacement of matching current history entries for both grouped and non-grouped memos, with guard handling and tests.
Contour stroke history integration packages/tools/src/utilities/contourSegmentation/applyContourStroke.ts	Tracks previous and resulting annotations and registers undo/redo callbacks that swap stored annotations through DefaultHistoryMemo.
Example undo and redo controls packages/tools/examples/planarFreehandContourSegmentationTool/index.ts	Adds toolbar buttons, keyboard shortcuts, and instructions for contour undo and redo.
Browser history validation and gesture support tests/vitest-browser/harness/tools.ts, tests/vitest-browser/undoRedoHistory.browser.test.ts, tests/vitest-browser/harness/createPlanarViewport.ts	Adds a drag-path helper, validates contour merge undo/redo behavior, and updates planar render backend enum usage.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant User
  participant applyStroke
  participant DefaultHistoryMemo
  participant AnnotationState
  User->>applyStroke: draw contour stroke
  applyStroke->>AnnotationState: create merged annotations
  applyStroke->>DefaultHistoryMemo: replace current memo
  User->>DefaultHistoryMemo: undo or redo
  DefaultHistoryMemo->>AnnotationState: restore previous or resulting annotations

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Possibly related PRs

• cornerstonejs/cornerstone3D#2742: Modifies the contour stroke boolean and annotation logic used by this PR’s undo/redo integration.

Suggested reviewers: wayfarer3130

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/fix-contour-segmentation-undo-redo

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