Add scale tool

[deanblackborough]

• Added a simple scale tool
• Updated the notes and readme

Summary by CodeRabbit

• New Features
  • Added a Scale tool to the editor, with on-canvas resize handles for eligible selected objects.
  • Scaling is integrated with the existing inspector size controls (width/height), enabling the correct UI when scaling is supported.
  • Updated the editor toolbar/palette layout to include the new Scale tool button and adjust its placement.
• Bug Fixes
  • Improved drag interactions so scaling and moving use the correct interaction mode, with scaling taking priority.
  • Suppressed move gizmos for multi-selection while in Scale mode.
• Documentation
  • Refreshed planning and readiness checklists across DECISIONS.md, README.md, and NOTES.md.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 000ca289-2f7a-47fb-bb44-543994fec342

📥 Commits

Reviewing files that changed from the base of the PR and between 24b50c7 and 441f80b.

📒 Files selected for processing (1)

• NOTES.md

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📝 Walkthrough

Walkthrough

This PR adds a Scale editor tool, scale-handle geometry, and drag-state support for scaling selected objects. Scene interaction now detects scale handles, updates objects during scale drags, and records move or size-change commands on drag end. The selected gizmo rendering, inspector size controls, and editor tool palette are updated for the scale tool, and the README/DECISIONS notes are revised.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

• deanblackborough/Prune#35: Shares the SceneState/DragState area that this PR extends with DragMode, scale_handle, and scale-start snapshots.
• deanblackborough/Prune#37: Extends the SceneInteraction drag flow that this PR now branches into move and scale modes.
• deanblackborough/Prune#78: Touches the same SceneInteraction drag and command-recording path that now branches between move and scale drags.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is concise and accurately reflects the main change: adding a scale tool to the editor.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch scale-tool

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[coderabbitai]

Actionable comments posted: 2

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 35d1d45c-8a67-4240-abd7-1a6fde9a6f76

📥 Commits

Reviewing files that changed from the base of the PR and between b1dc3aa and a6bf4fb.

📒 Files selected for processing (12)

• DECISIONS.md
• README.md
• src/prune/editor/editor_tool.hpp
• src/prune/editor/tools/transform_gizmo.hpp
• src/prune/scene/scene.hpp
• src/prune/scene/scene_interaction.cpp
• src/prune/scene/scene_interaction.hpp
• src/prune/scene/scene_renderer.cpp
• src/prune/scene/scene_renderer.hpp
• src/prune/scene/scene_state.hpp
• src/prune/tooling/inspector.cpp
• src/prune/tooling/ui.cpp

[coderabbitai]

Actionable comments posted: 1

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro

Run ID: 37b02c90-1cbf-4949-b923-6f0fbece1a66

📥 Commits

Reviewing files that changed from the base of the PR and between a6bf4fb and 24b50c7.

📒 Files selected for processing (4)

• NOTES.md
• README.md
• src/prune/scene/scene_interaction.cpp
• src/prune/scene/scene_interaction.hpp