M4.88: Object → Slice makes, edits and lays out user, object and auto slices

Document.slices holds user slices, Node.slice makes an object an object
slice that follows its bounds, and Document.slices_clip_to_artboard picks
the region auto slices fill (the artboards, or the art and the slices).
Object → Slice: Make, Release, Create from Guides, Create from Selection,
Duplicate, Combine, Divide… (dialog), Delete All, Slice Options… (dialog)
and Clip to Artboard; View → Hide/Lock Slices; Select → Object → Slices;
slice.list reads the numbered layout. The canvas draws the slices in the
Slices preferences' line colour with their numbers.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/control-protocol.md

@@ -318,3 +318,10 @@ gets a `confirm` dialog whose OK runs `file.saveAs`). Fields: `folder` (the loca
 `copyLinks`, `linksFolder`, `relink`, `copyFonts`, `report`. `ui.dialog.confirm` saves unsaved changes, runs
 `file.package` and then opens a `confirm` dialog whose OK runs `file.showPackage {folder}`; the web downloads the zip
 instead. Document Info's flyout picks a category and Save… runs `docInfo.save {path?, selectionOnly?}`.
+
+Slices: through the app, `object.slice.options` and `object.slice.divide` with no params open their dialogs on the
+selected slices. `sliceOptions` (fields `kind`: `image`/`noImage`/`htmlText`, `name`, `url`, `target`, `message`,
+`alt`, `text`, `background`: `""`/`matte`/`#rrggbb`, `hAlign`, `vAlign`; `__html` says whether HTML Text applies)
+runs `object.slice.options` on `ui.dialog.confirm`; `divideSlices` (fields `divideRows`, `rows`, `rowMode`:
+`count`/`size`, `rowHeight`, and `divideColumns`, `columns`, `columnMode`, `columnWidth`) runs `object.slice.divide`.
+Read slice options with `slice.list`.

docs/mcp.md

@@ -1114,3 +1114,27 @@ the package report write.
 {"name":"run_command","arguments":{"command":"document.info","params":{"format":"text","category":"fontDetails"}}}
 ```
 
+## Slices
+
+Object → Slice cuts the art into the pieces web output saves. User slices are rectangles of their own
+(`document.slices`, ids from the object id counter); `object.slice.make` turns the selected objects into object
+slices, whose slice follows the object's bounds; auto slices fill what no other slice covers (the artboards with
+Clip to Artboard on, the default, else the art and the slices). `slice.list` returns every slice as laid out,
+numbered left to right and top to bottom: `{number, id (null for auto slices), source: user|object|auto, name, x, y,
+width, height, options, selected}`, plus `clipToArtboard`, `hidden` and `locked`.
+
+The Object → Slice commands act on the selected slices: the ones `select.object.slices` (Select → Object → Slices)
+selects, and the selected objects that are object slices. `object.slice.release` (an object slice leaves its object,
+a user slice becomes an unpainted rectangle), `object.slice.fromGuides` (the grid the ruler guides cut the artboards
+into), `object.slice.fromSelection`, `object.slice.duplicate {dx?, dy?}`, `object.slice.combine`,
+`object.slice.divide {rows? | rowHeight?, columns? | columnWidth?}`, `object.slice.deleteAll`,
+`object.slice.options {kind?: image|noImage|htmlText, name?, url?, target?, message?, alt?, text?, background?:
+""|matte|#rrggbb, hAlign?, vAlign?}` and `object.slice.clipToArtboard {on?}` are each one undo step.
+`view.slices.hide {hidden?}` and `view.slices.lock {locked?}` are session view state; the canvas draws the slices in
+the `sliceLineColor` preference, numbered while `showSliceNumbers` is on.
+
+```json
+{"name":"run_command","arguments":{"command":"object.slice.make","params":{}}}
+{"name":"run_command","arguments":{"command":"object.slice.options","params":{"name":"logo","url":"https://example.com","alt":"Logo"}}}
+{"name":"run_command","arguments":{"command":"slice.list","params":{}}}
+```