Merge pull request #7080 from dotCooCoo/feat/trace-create-strokes

Image Trace: Create Strokes makes a wide shape's thin features strokes and keeps its body a fill

docs/target-app-parity.md

@@ -1351,6 +1351,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   A blend in a `.ai` or EPS opened from its editing data keeps a Specified Distance spacing with its distance ([Blend Options](https://helpx.adobe.com/illustrator/desktop/manage-colors/apply-transparency-and-blending/blend-options-overview.html)) where VectorCraft lays out as many steps between each pair of keys as the file draws, in the same places and colors. A Smooth Color blend opens live only where VectorCraft's own Smooth Color step count equals the drawn steps, and VectorCraft often counts a different number. A blend that VectorCraft doesn't lay out as drawn keeps its drawn steps with a note (`import::ai::tests::a_blend_keeps_its_spacing`, `a_blend_of_three_keys_keeps_its_distance_between_each_pair`, `a_blend_whose_spacing_doesnt_lay_out_its_steps_keeps_them`).
 
   - Create Strokes uses exact squared Euclidean distances and Guo–Hall thinning in bounded per-blob crops. Maximal-disc pruning, split-crossing merges and degree-two joins simplify its skeleton graph. The whole-blob width rule and ink fitting remain; 46 code-drawn inputs measure ends and junctions in [`image-trace-quality.md`](image-trace-quality.md#centre-lines). Junction degrees measure 44/45 correct in each input variant; remaining spurs are recorded. This is a measured skeleton improvement; the Image Trace score, missing per-feature selection and width controls, and estimates remain unchanged.
+  - Create Strokes decides stroke or fill per feature, as the [help page](https://helpx.adobe.com/illustrator/desktop/manage-objects/traces-mockups-symbols/image-trace-panel-options.html) describes the Strokes width: the widest feature of the image that can become a stroke. A shape wider than Stroke somewhere keeps as its area every disc wider than Stroke that fits in it, and each piece outside those discs that reaches out of them at least one and a half times its own width (and 3 px) is traced as a stroked center line, its end at the area carried to the cut so the line's cap closes the join. Corners and edge slivers stay in the area. Which pieces count as features is VectorCraft's own rule. Each line still has one width; without Fills, the area is a 1 px outline as before. Tests: `thin_features_of_a_wide_shape_are_strokes_and_its_body_a_fill`, `wide_shapes_without_thin_features_stay_one_fill` and `distances_to_seeds_equal_brute_force` in `vectorcraft-trace`. The Image Trace score and estimates are unchanged.
   Object › Live Paint › Merge adds the other selected paths and Live Paint groups to the bottom selected Live Paint group ([Live Paint groups](https://web.archive.org/web/20241230205225/https://helpx.adobe.com/illustrator/using/live-paint-groups.html)), which keeps its id, the paint of its faces and edges, and its name, lock, visibility, transparency, appearance, opacity mask and graphic style link. Object › Live Paint › Make with a Live Paint group selected, and a Live Paint Bucket click on a selected path beside a selected Live Paint group, add the paths to that group the same way. Make, Merge and the Live Paint Bucket take paths, compound paths and groups of them; with type, an image or another object among the selection they report that it has to be converted to paths first and change nothing, as type and raster images can't go into a Live Paint group directly ([Create Live Paint groups](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/learn-painting-basics/create-live-paint-groups.html)); before, such an object went among the group's hidden sources and vanished from the canvas. Evidence: `tests_build::live_paint_refuses_type_and_images_and_changes_nothing`.
   With the Live Paint Bucket selected, Alt-click on vector art samples its fill, stroke and stroke weight into the paint defaults ([Paint with the Live Paint Bucket tool](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/learn-painting-basics/paint-with-the-live-paint-bucket-tool.html)). On a placed image it samples the image pixel as a solid fill with no stroke. Alt+Shift-click samples only the color under the pointer, including an intermediate gradient color or image pixels, into the active fill or stroke ([Default keyboard shortcuts](https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html)). Neither click paints or changes the selection or selected art, and the next Bucket click paints with the sampled paint. Evidence: `tests_build::live_paint_bucket_alt_sample_paints_next_face_without_changing_selection`.
   Double-clicking the Live Paint Bucket opens Live Paint Bucket Options ([Paint with the Live Paint Bucket tool](https://helpx.adobe.com/illustrator/desktop/paint-and-fill/learn-painting-basics/paint-with-the-live-paint-bucket-tool.html)): Paint Fills (on) and Paint Strokes (off) set whether a click paints faces, edges or both, Highlight turns the outline of the face or edge under the pointer on or off, and Color and Width set it (red and 4 px by default). Faces are outlined at the Width and edges at half of it, as the page says faces are highlighted with a thick line and edges with a thin line. With both on, a click paints the edge within 4 px of the pointer, else the face, and Shift switches to Paint Fills only; with one on, Shift switches to the other. The options last across tool switches and are saved with the preferences (`tool.setOption {tool: "livePaintBucket"}`). Evidence: `builder::tests::{bucket_options_choose_what_a_click_paints, bucket_options_set_the_highlight, bucket_highlights_an_edge_thinner_than_a_face}`, `dialogs::live_paint_bucket::tests::double_clicking_the_tool_opens_its_options_and_ok_sets_them`.