72ad6bb611
Pen, highlighter, line, arrow, rectangle, ellipse, text, eraser, undo/redo, colours, widths, clear (click twice); debounced save, damaged-sidecar notice, image-changed notice, read-only shows marks without tools. The sidecar is read and written through Vault on a worker thread (the view cannot reach the engine commands). Built by MiniMax M3.1 Flash (OpenCode Zen free route); verified from a clean checkout of the staged files: 901 lib tests, image_annotate 5 and image_view 5 pass, xtask i18n and tree clean. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>