Rarely set fields move into one optional boxed NodeExtras, and large NodeKind payloads (images,
live shapes, blends, envelopes) are boxed. Every object, and every undo step that copies it,
shrinks: a 50k-path move keeps ~24.5 MB per step instead of ~40 MB. Files stay byte-identical
(Node keeps its flat JSON through a borrowed Serialize and a from-wire Deserialize, no flatten),
and loading is slightly faster. Undo and redo reuse their step's size estimate instead of
walking the document again (8.3 -> 5.6 ms for a 50k-path move).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VmMmc1J8XeNLxhRihWv9cc
# Conflicts:
# crates/engine/src/cmd/graph.rs
# crates/svg/src/export.rs
Same treatment as the branch's `as_chunks` commit (Rust 1.99's
`chunks_exact_to_as_chunks` lint) for the flattener's coverage pass, the
CMYK ink compositor, the Flattener Preview highlight and four test helpers.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
object.flattenTransparency {preset?|options, ids?} splits the targets into groups of overlapping
objects. Groups with transparency become atomic regions (faces of the arrangement of every fill,
outlined stroke and clipping path) filled with the colour the renderer composites there: blend
modes, group opacity, isolated and non-isolated groups, knockout groups and knockout shapes, over
white or (Preserve Alpha) over nothing. Regions reached by gradients, patterns, images, opacity
masks or raster effects are rendered into one image per group, under the regions, clipped to
them with Clip Complex Regions. The raster/vector balance rasterizes whole groups past its region
budget (all at 0). Options and presets live in FlattenOptions; single visible paints keep their
colour and overprint; text and strokes can be outlined everywhere. One undo step.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>