[mayokunl]

Pull Request Summary

Closes #426
Closes #427
Closes #428
Closes #429
Closes #430
Closes #431
Closes #432
Closes #433
Closes #434
Closes #435
Closes #436
Closes #437
Closes #438

What: Editors can now add and edit annotations in the Scene Editor: text labels, straight lines, pointer lines that connect a label to a feature, arrows, and see-through highlight regions. Each one can be selected and moved, reshaped, styled, reordered, or deleted.

Why: Until now, scenes could only hold images, plus annotations imported from existing bones that couldn't be edited. Editors need to mark up bone images themselves to identify anatomical structures.

How: A new Add annotation row picks a tool, and a toolbar shows controls for whatever is selected. Every change edits the scene's working copy and is stored with the next Save, the same as image edits (#451). No server changes were needed.

Testing: Two new test files cover each sub-issue end to end, including saving and reopening the scene. Full suite: 742 passed, 5 skipped. ESLint passes.

Screenshots

PR Checklist

• Project builds and runs
• Tests and linters pass
• Any related documentation has been updated, including JSDoc comments or docstrings

Detailed Description

Features by issue

Issue	What it does
#427 Create text label	Click Text label, then click the canvas. The label is placed there, selected, with its text ready to type over. Multi-line text works.
#428 Edit label text	Edit in the toolbar's Text box, or double-click the label. An empty label isn't applied: an error shows and the last text is kept.
#429 Move and resize labels	Drag the label or use the arrow keys (Shift moves 10px). Resize with the corner handle or the Text size field (8–200px).
#430 / #437 Delete	Delete annotation button or the Delete key. Other annotations, and other scenes, are unaffected.
#431 Straight line	Drag to draw. Each end has a handle, and the whole line can be dragged.
#432 Pointer line	Select a label, click Add pointer line, then click the feature. Moving the label moves the line's label end, and deleting the label deletes its pointer lines. Labels imported from existing bones work the same way.
#433 Arrow	Drag from the tail to where it points. The head is drawn at the end.
#434 Highlight region	Click each corner, then finish with Finish shape, Enter, double-click, or a click on the first corner. Escape cancels; Backspace removes the last corner.
#435 Edit a region	Drag a corner handle, or drag the whole shape.
#436 Style a region	Color picker and fill opacity. Opacity is capped at 0.8 so the bone stays visible. Labels, lines, and arrows have a color picker too.
#438 Layer order	Send to back, backward, forward, or bring to front. Annotations always draw above images, so image order never changes.

[mudabs]

Thank you Mayo for the substantial work on the annotation editor. The new label, line, arrow, pointer-line, and highlight functionality is a meaningful addition, and the accompanying tests make the behavior much easier to review.

I’m requesting one local behavior fix before approval. This is independent of the database/object-storage discussion; that can be handled in a separate follow-up issue.

File: templates/js/scenes.js

The issue involves:

• cancelTool() around line 1404
• setTool() around line 1387
• startLineDraw() around line 1475
• handleAnnotationKey() around line 1776

startLineDraw() registers document-level mousemove and mouseup listeners. However, cancelTool() and setTool() clear state.draft without removing those listeners.

This creates a reproducible failure:

1. Open a scene and select the Line or Arrow tool.
2. Begin dragging on the canvas.
3. Press Escape before releasing the mouse.
4. Move the mouse again.

Escape calls cancelTool(), which sets state.draft to null. The existing mousemove listener remains active and then executes state.draft.points[1] = ..., causing a TypeError because state.draft is null.

Switching tools while a line or arrow drag is active can leave the same kind of stale listener behind.

Please centralize the cleanup for an active line/arrow drag so that:

• cancelTool() removes any active document-level drag listeners.
• setTool() also cleans up an existing drag before replacing the current tool.
• Normal mouseup remains safe and idempotent.
• The draft state is cleared without allowing later mousemove events to access it.

Please add a regression test in templates/tests/sceneAnnotationEditor.test.js, near the existing line/arrow drawing tests. The test should start a line or arrow drag, press Escape, dispatch another mousemove/mouseup, and verify that no exception occurs and no annotation is created. It would also be useful to cover switching tools during an active drag.

The current local scene persistence and the existing base64 image approach can remain unchanged for this PR. Production image storage/database changes should be tracked separately.

Thank you again for the effort on this feature.