Unify preview-aware transforms across scene drawing, labels, selection and input. Give live property and creation edits explicit preview ownership, preserve cancellation and one-step undo, and reuse bounded text preparation resources.
Include retained device-grid handling, worktree HMR coverage, and nested/reflected interaction regressions in this cohesive progress checkpoint.
Validation: full check passes; 734 scoped unit tests and 53 targeted browser tests pass. This is NOT merge-ready: the unchanged exact nested filled-section held/released regression still fails with 63 differing pixels (maximum channel delta 5/255). The browser pass count excludes that separately run failure and the previously classified paint-field-width baseline. Raster-origin investigation and broader acceptance remain outstanding.
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