Libraries: gradients and patterns can be added to a library and applied from it

Squashed from #4442 onto main.

docs/mcp.md

@@ -2024,7 +2024,8 @@ they answer its file's name without the extension and `count: 0`.
 
 ## Libraries
 
-The Libraries panel's libraries hold graphics, colours and character and paragraph styles that any document can use.
+The Libraries panel's libraries hold graphics, colours, gradients, patterns and character and paragraph styles that any
+document can use.
 They are kept on this machine: each is a `.vclibrary` file (JSON) named after the library (`CON-.vclibrary` for a
 library named after a Windows device such as `CON`) in the `Libraries` folder next to the preferences
 (none in the web app and headless sessions, where they last for the session). `library.list` lists them (`id`, `name`,
@@ -2034,7 +2035,7 @@ size and a PNG `thumbnail` in base64; colours with `name`, `hex` and `color`; st
 `library.setCurrent {library}` manage them; `library` is an id or a name, and without it the current library (the one
 the panel shows) is meant.
 
-`library.add {library?, kind, ids?, name?, color?}` adds from the selection: `graphic` (a copy of the objects with the
+`library.add {library?, kind, ids?, name?, color?, swatch?}` adds from the selection: `graphic` (a copy of the objects with the
 images, symbols, patterns, swatches, styles and brushes they use, as Copy takes them), `fillColor` / `strokeColor` (the
 first selected object's solid colour, else the default one, or `color`), `charStyle` / `paraStyle` (the selected
 text's attributes). An item the library already has is reported as `existing`. `library.use {library?, kind, item,
@@ -2044,6 +2045,18 @@ to the document under its name without the white space around it (numbered when
 attributes) and applied to the selected text, each as one undo step. `library.removeItem {library?, kind, item}` removes
 one.
 
+Gradients and patterns are kinds of their own (the panel's + button lists Fill Gradient, Stroke Gradient, Fill Pattern
+and Stroke Pattern, and a gradient or pattern swatch dragged from the Swatches panel onto the list is added).
+`library.add {kind: "fillGradient" | "strokeGradient", swatch?}` adds the first selected object's fill or stroke
+gradient (else the default one, or the gradient swatch `swatch`) without its placement or swatch links, named after its
+swatch, else `Gradient`; `library.use` paints the selection's fill or stroke with it, fitted to each object.
+`library.add {kind: "fillPattern" | "strokePattern", swatch?}` adds the first selected object's fill or stroke pattern
+(else the default one, or the pattern swatch `swatch`) with the images, symbols, patterns, swatches, styles and brushes
+its art uses, and a thumbnail of one swatch's worth of it; `library.use` adds the pattern and its swatch to the document (the
+same pattern there is reused, and a name the document gives another pattern gets a number) and paints the selection's
+fill or stroke with it, as one undo step, and returns the pattern's name in the document as `pattern`. `library.get`
+lists them as `gradients: [{name, gradient}]` and `patterns: [{name, pattern, thumbnail}]`.
+
 Items can be put in user-named groups, which the panel shows as collapsible sections after the ungrouped items (its
 search field filters every item by name; `library.get` lists them all to filter). `library.createGroup {library?,
 name?, items?: [{kind, item}]}` makes one (a name another group has, ignoring case, gets a number) with those items
@@ -2053,15 +2066,17 @@ deletes one, its items staying in the library ungrouped; and `library.moveItem {
 of its kind), just before or after that item in the order its kind is listed and shown in. `library.moveGroup
 {library?, group, to}` moves a group to place `to` of the list (0: first; past the end: last). Dragging items and
 group headers in the panel runs these. An item is in one group at most; `library.get` lists the groups as `groups:
-[{name, items: [{kind: "color"|"charStyle"|"paraStyle"|"graphic", item}]}]` (a graphic by its id), and each kind's
+[{name, items: [{kind: "color"|"gradient"|"pattern"|"charStyle"|"paraStyle"|"graphic", item}]}]` (a graphic by its id), and each kind's
 items in the order the panel shows them.
 
-`library.export {library?, path?}` writes a library (its colours, styles, graphics with their art and thumbnails, and
-its groups) as a `.vclibrary` file, the JSON the library folder keeps (without `path`: `{data}`, the file's text).
+`library.export {library?, path?}` writes a library (its colours, gradients, patterns, styles, graphics with their art
+and thumbnails, and its groups) as a `.vclibrary` file, the JSON the library folder keeps (without `path`: `{data}`, the file's text).
 `library.import {path? | data? | dataBase64?, name?}` adds the library of such a file as a new library and makes it
 the current one; a name another library has gets a number (`Brand (2)`). Imported files are checked: at most 10,000
-items of each kind and 1,000 groups, names clipped and made unique, thumbnails kept only when they are small PNGs, and
-groups naming items that aren't there dropped. Files written before groups load as they are.
+items of each kind and 1,000 groups, names clipped and made unique, thumbnails kept only when they are small PNGs,
+gradients with fewer than 2 or more than 1,024 stops dropped and the others' offsets, opacities and midpoints put in
+range, and groups naming items that aren't there dropped. Files written before groups load as they are. Using a
+pattern whose data is damaged fails with an error and leaves the document as it was.
 
 ```json
 {"name":"run_command","arguments":{"command":"library.add","params":{"kind":"graphic","name":"Logo"}}}

docs/target-app-parity.md

@@ -929,6 +929,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     In the Graphic Styles panel, Shift-click selects a range of styles and Ctrl/Cmd-click adds or removes one.
   - **Neutral wording:** labels, MCP tool text, docs and packaging use neutral names, and `cargo xtask brands` (part of `cargo xtask ci`) fails on vendor names.
 - **Colour, type and file workflows:** Recolor Artwork (dialog with harmonies), Edit Colors, Find & Replace, Change Case, Smart Punctuation, Guides, Lock/Hide Above, Transform Each, Rasterize.
+  The Libraries panel holds gradients and patterns: its + button adds the selection's fill or stroke gradient or pattern, a gradient or pattern swatch dragged from the Swatches panel is added, and a click paints the selection through the active Fill/Stroke proxy, a pattern bringing its definition and swatch into the document.
   Object › Lock › All Artwork Above and Object › Hide › All Artwork Above deselect the selected objects they lock or hide, the key object included.
   Object › Hide › Unselected Artwork (Cmd/Ctrl+Alt+Shift+3, `object.hide.unselected`) hides, in one undo step, every object Select All takes that is not selected and holds no selected object; the members of a group that holds a selected object are hidden one by one, and Object › Show All shows them again. It is disabled in isolation mode. Public references: [Default keyboard shortcuts](https://web.archive.org/web/20260726060015/https://helpx.adobe.com/illustrator/using/default-keyboard-shortcuts.html), "Hide unselected artwork"; [How to lock, hide, and delete objects in Illustrator](https://web.archive.org/web/20220303070637/https://helpx.adobe.com/illustrator/using/locking-hiding-deleting-objects.html), which says the Show All and Hide menus are unavailable in isolation mode.
   In isolation mode, the items of Object › Lock and Object › Hide, Unlock All and Show All are greyed out ([lock, hide, and delete objects](https://web.archive.org/web/20220303070637/https://helpx.adobe.com/illustrator/using/locking-hiding-deleting-objects.html)); the Contextual Task Bar's Lock button is greyed out too, the Properties panel's Quick Actions have no Lock, and the commands return an error. Pattern editing mode and opacity mask editing do not count as isolation mode for them.