Effects: a symbol instance's fill or stroke effects reshape its art and expand

A geometry effect on a symbol instance's topmost fill now reshapes the
filled shapes of the symbol's art, and one on its topmost stroke reshapes
the stroked shapes, keeping their colors, strokes and other detail. Only
a visible topmost fill or stroke with an opacity above 0 counts. Clipping
paths, guides and opacity-mask art keep their shapes; a group's own fills
and strokes in the art take the effects; a nested instance passes them on
to its own art, except one whose symbol holds the outer symbol.

The canvas, Use Preview Bounds and the drawn bounds, SVG and PDF export
and Object > Expand Appearance use the same art. Expand Appearance is
enabled for such an instance and turns it into an editable group in one
undo step. Bounds measure the art with a dynamic symbol's overrides, as
the canvas draws it.

Existing documents with a geometry effect on a symbol instance's fill or
stroke draw differently: before, the effect drew nothing.

docs/mcp.md

@@ -4269,7 +4269,10 @@ document's raster effects resolution (shadows and outer glows under the art; a b
 the object with the image). Type with a geometry effect (Outline Object included) or with fills and strokes of its own
 is outlined; type that has no fills or strokes of its own and whose only effects are shadows or outer glows stays
 type, with the image under it. A group's or layer's own fills and strokes become objects among its members, and its
-members are expanded too. The result is `{ids}`; when an image in the art can't be decoded, the images made from
+members are expanded too. A symbol instance whose topmost fill or topmost stroke is visible, has an opacity above 0
+and has a geometry effect becomes a group of its art: that fill's effects reshape the filled shapes of the art and that
+stroke's effects reshape its stroked shapes, which keep their colors, as the canvas draws them (VectorCraft's own
+rule); the instance's other fills and strokes are dropped. The result is `{ids}`; when an image in the art can't be decoded, the images made from
 raster effects do not show it, and the result also carries the `warning` that Flatten Transparency gives.
 A path's strokes stay strokes, as the
 [Expand objects](https://helpx.adobe.com/illustrator/desktop/manage-objects/arrange-objects/expand-objects.html) help

docs/target-app-parity.md

@@ -1421,6 +1421,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     The Add New Effect popup (Appearance panel, Properties), the Appearance panel's swatch picker, the Gradient panel's gradient swatches menu and the Image Trace button's list of presets stop at the bottom of a short window, and the mouse wheel or the scroll bar reaches their last rows. A list that fits does not scroll (`a_long_swatch_picker_scrolls_inside_a_short_window`).
     An image's own fills and strokes draw the shape that a Convert to Shape or Outline Object effect on them gives them (the image's box or its frame, reshaped by the effects after it), under or over the image as its Contents row says, on the canvas, in exports and through Expand Appearance; new fills and strokes on an image go under it. Without one of those effects they draw nothing, and Use Preview Bounds measures an image by its frame.
     A geometry effect on one of type's own fills or strokes reshapes the whole outline that the fill or stroke paints, on the canvas and in exports; PDF, SVG, EPS and the other vector exports write such type as paths. On type that holds inline graphics, those effects are drawn and exported only when the type has a geometry effect or perspective of its own.
+    A geometry effect on a symbol instance's fill reshapes the filled shapes of the symbol's art and leaves their strokes as they are; one on the instance's stroke reshapes the stroked shapes and leaves their fills as they are. The shapes keep their colors. Only the instance's topmost fill and topmost stroke count, and only while they are visible with an opacity above 0. The canvas and Object › Expand Appearance use the same art, SVG and PDF export bake the same shapes, and Expand Appearance turns the instance into an editable group in one undo step. A group's own fills and strokes in the art take the effects too. An instance inside the art passes the effects on to its own art, and a dynamic symbol's instance reshapes the fills and strokes it paints on the art. How the effects map onto the symbol's art is VectorCraft's own rule. The help page <https://helpx.adobe.com/illustrator/desktop/special-effects-styles/apply-filter-effects/apply-and-modify-effects.html> describes effects on one fill or stroke, and the help page <https://helpx.adobe.com/illustrator/desktop/manage-objects/arrange-objects/expand-objects.html> describes Expand Appearance (engine `expand::a_symbol_instance_fill_effect_reshapes_its_filled_art_and_expands`, `a_symbol_instance_stroke_effect_reshapes_its_stroked_art_and_expands`, `a_stroke_effect_reshapes_a_stroke_a_dynamic_instance_adds`, `a_fill_effect_reshapes_the_fill_of_a_group_in_the_art`, `only_the_topmost_visible_instance_fill_reshapes_the_art`, `a_nested_symbol_instance_takes_the_outer_fill_effect`, `export_bakes_a_symbol_instance_fill_effect`, `a_fill_effect_on_an_instance_of_a_symbol_that_holds_itself_ends`). Existing documents with a geometry effect on a symbol instance's fill or stroke draw differently: before, the effect drew nothing.
     The Appearance panel's inline effect editor labels each parameter as the effect dialogs' generic fields do, without the colon ("Max. Radius", "Channel 1", "Create New Fields by"). Roughen's and Zig Zag's Points, Offset Path's Joins, Inner Glow's Source and the menus of Radial Blur, Smart Blur, Sprayed Strokes, Glass, Mezzotint, Halftone Pattern, Grain, Texturizer and De-Interlace are dropdowns with the dialog's labels that send the dialog's values, and a plug-in's choice is a dropdown of the plug-in's values.
     Revolve's edge, Extrude & Bevel's bevel, every Warp style's orientation, Rasterize's Color Model, Background and Anti-aliasing and the channel of Levels and Curves are dropdowns too, with the labels their own dialogs show. `effect.apply` and `effect.setParams` refuse a Levels or Curves `channel` other than `rgb`, `red`, `green` or `blue` (or `r`, `g` and `b`, in any letter case).
     Object › Expand Appearance keeps each stroke of a path a stroke (weight, caps, joins, dashes, arrowheads, alignment and width profile) on a copy of the path with the geometry effects baked in, and Object › Expand… is dimmed, with a tooltip, while the selection has appearance attributes, so a stroked line with Zig Zag becomes a stroked zig-zag line and only Expand then outlines it, the two steps the [Expand objects](https://helpx.adobe.com/illustrator/desktop/manage-objects/arrange-objects/expand-objects.html) help page describes (#3089). Brushed strokes still become their brush art; `object.expand` still bakes and outlines in one step for agents.