Symbols: instances of imported symbols are measured by their art

Every symbol instance was measured as its transform applied to the
20 × 20 square around the origin, which symbols made in the app keep
their art in. The SVG and DXF importers keep symbol art as drawn, so
the box of an instance of an imported symbol did not match its art.
The SVG Star instance at x 20, y 30 draws from (20, 30) to (40, 50)
and was measured from (10, 20) to (30, 40). Align moved such an
instance by the wrong amount, clicks and marquees beside its art
selected it, and the canvas, exports and prints left it out when its
art reached the view or the page and the square did not.

An instance is now measured by its symbol's art, which
Document::symbol_boxes looks up in the document each time
(Node::geometric_bounds_with, visual_bounds_with and
reach_bounds_with). With Use Preview Bounds on, the strokes in the art
count at their own weight, as the canvas draws them, and
object.setBounds counts them at that weight when it sizes an instance
or an object that holds one. When strokes do not scale and a width or
height of 0 or more is smaller than what a path's stroke adds,
object.setBounds now gives the path no width or height, as it does
for an instance whose art has strokes; before, it mirrored the path.
With Use Preview Bounds on, object.setBounds now measures the margins
that strokes add object by object, the members of groups and the
objects in symbol instances' art included, and solves for the width,
height and reference point asked for when the width and height are 0
or more. Before, it measured the margins of the whole selection and
could miss the size or the reference point asked for when strokes did
not scale and the objects' strokes added different margins, and when
strokes scaled and the width and height were out of proportion, even
for one path. A clip group, a Shaper Group, a compound path, type, and
a group or instance with effects or an opacity mask of its own are each
measured as one object, and so is an instance in perspective or one
turned or slanted relative to the bounding box, other than by quarter
turns. When the selection holds more than 4,096 objects to measure this
way, each selected object is measured as one. Instances inside symbol
art are measured by their own symbol's art. An instance is measured as
the square when its symbol is missing, when its symbol or a symbol
nested in its art holds an instance of itself, and when symbols nest 32
deep in its art.

Align and Distribute, the Transform panel, the bounding box and the
selection outline, clicks, the marquee, document.inspect and
document.node, Fit to Artwork Bounds and Fit to Selected Art, canvas
culling, thumbnails, the SVG filter region of an instance with a
raster effect, raster effect images, Export Selection, the SVG of an
artboard, printing, and the PDF, EPS, EMF/WMF and DXF writers use the
new box. The renderer also culls an instance by the effects and
brushed strokes in its art, and it culls a blend, envelope or repeat
by the brush art of what it holds and the effects in the art of the
instances in it. It culls an instance with geometry effects of its own
by the effects in its art after those geometry effects reshape the art.
It measures the effects in a symbol's art once for each symbol and
linear part of the transform that places it. For symbols whose art
holds instances, it measures at most 4,096 placements a frame, and at
most 4,096 more for each pattern tile it rasterizes and each placed
document it draws. Past that, it estimates the reach from the symbol's
reach with no transform, which it measures once. When the drawn
document's symbols change, the renderer drops the cached bounds of the
instances and of the objects that hold them.

The PDF and EPS writers, the SVG of an artboard and Skip Blank
Artboards grow the box of an instance whose art holds brushed strokes
by 16 times the widest stroke (at least 1 pt) of the objects in that
art that have a brushed stroke, plus 8 pt, as the renderer grows the
cull bounds of a brushed path. They keep an instance whose brush art
reaches the page. The SVG of an artboard also keeps an object that
holds an instance when what the canvas paints for it, the effects in
the symbol's art and the instance's own included, reaches the artboard.

Not yet: other commands that measure objects, such as Select › All on
Active Artboard, Transform Each and Convert to Artboards, still measure
an instance by the square.

Docs: docs/mcp.md, docs/target-app-parity.md.

docs/mcp.md

@@ -1464,6 +1464,18 @@ in the whole stroke as drawn: arrowheads, inside/outside alignment (an outside s
 inside one inside it), the width profile's width where you click, projecting caps and miter spikes up to the miter
 limit. A rectangle's right-angle miters stay within half the weight of its edges.
 
+A symbol instance is measured by its symbol's art, placed by the instance's transform. The bounds in
+`document.inspect` and `document.node`, the Align commands, `object.setBounds`, the bounding box, clicks, marquees,
+Fit to Artwork Bounds and exports of the art use that box. Visual bounds (Use Preview Bounds, Fit to Selected Art)
+take in the strokes in the art at their own weight, as the canvas draws them when the instance scales the art. An
+instance is measured as the 20 × 20 square around the origin, which symbols made in the app keep their art in, when
+its symbol is missing, when its symbol or a symbol nested in its art holds an instance of itself, and when symbols
+nest 32 deep in its art. PDF and EPS export and the SVG of an artboard leave out art outside the page or artboard, and
+Skip Blank Artboards skips an artboard with no art on it. For both, the box of an instance whose art holds brushed
+strokes grows by 16 times the widest stroke (at least 1 pt) of the objects in its art that have a brushed stroke,
+plus 8 pt. The SVG of an artboard also keeps an object that holds an instance when the effects in the symbol's art, or
+the instance's own, paint onto the artboard.
+
 ## Expand
 
 `object.expand {object?, fill?, stroke?, gradient?, steps?}` (Object → Expand…) turns the selection into plain art in

docs/target-app-parity.md

@@ -426,6 +426,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     The Select menu's Same commands, its Object commands that select art, Next Object Above and Below and saved selections select only objects that Select All selects and objects inside them: nothing hidden or locked, nothing in a hidden or locked group, layer or sublayer, nothing on a template layer, and in isolation mode nothing outside the isolated group or layer. In isolation mode Select All, All on Active Artboard and Inverse select nothing while the isolated group or layer, or a group or layer it is in, is hidden, locked or a template layer.
     Align and Distribute Spacing keep a compound path or selected group that contains the key object in place, as they keep the key object itself.
     Anchor Align moves the selected points to their bounds or the artboard (#1180). Repeating it, or moving by at most 1e-9 pt on both axes as whole-object Align does, leaves the document, Undo, Redo and saved state unchanged; actual moves still take one undo step. `crates/engine/src/tests.rs` covers repeated alignment, rounding-only alignment, unchanged handles, saved state, command recording and Undo/Redo.
+    A symbol instance is measured by its symbol's art, as its transform places it, for clicks, the marquee, the bounding box, the Transform panel, Align and Distribute (the art's strokes too with Use Preview Bounds), Fit to Artwork Bounds, exports of the art, thumbnails and canvas culling; one whose symbol is missing is measured as the 20 × 20 square around the origin.
     Clear deletes individual selected compound-path members without deleting their siblings, and explicit object ids work without a selection; Cut still removes the same objects it copies (#786).
   - **Compound paths:** Make keeps the backmost object's appearance and each contour; selecting a member in Direct Selection reads and changes the compound's fill rule in Attributes. Direction remains a per-member edit. Rendered holes, unchanged contour geometry, no-op history and Undo/Redo are covered by `engine/tests/compound_attributes.rs` (#1197). Behaviour reference: [public compound-path documentation](https://helpx.adobe.com/illustrator/desktop/manage-objects/reshape-transform-objects/create-compound-paths.html). Make Compound Path on a group (such as outlined type) keeps the paint of its backmost path instead of drawing nothing, and compound paths joined into one keep their holes (#1537).
   - **Saved selections:** Select ▸ Save Selection… asks for a name and keeps the selection in the document (saved with the file, undoable, up to 25); each one is listed at the bottom of the Select menu and a click selects its objects again; Edit Selection… lists them to rename or delete, applied together on OK. A file's saved selections are capped and checked against its objects when it opens. Not yet: Update Selection and the Layers panel's saved-selection menu.