Isolation mode: double-clicking a single object isolates it

With Double Click To Isolate on, the Selection tool isolated groups only. A
double-click on a single path, compound path, image, mesh or placed file now
isolates it too, as the public documentation describes. Type still switches to
the Type tool; blends, envelopes, repeats and symbol instances keep their own
editing modes.

While a single object is isolated only it is hit, marqueed and taken by Select
All, new art goes beside it in its group or layer, and a double-click on the
empty canvas leaves with it selected. object.isolate accepts any object except
type.

docs/mcp.md

@@ -1159,7 +1159,7 @@ and `layerRows`, the rows highlighted in the panel.
   `layer.reverse {ids?}`, `layer.template {ids?, on?}`, `layer.hideOthers` / `layer.showAll`,
   `layer.outlineOthers` / `layer.previewAll`, `layer.lockOthers` / `layer.unlockAll` (Alt-clicking an eye or a lock
   runs Hide or Lock Others for the row's layer, or Show or Unlock All when the others already are), `layer.pasteRemembersLayers`,
-  `object.isolate {id}` / `object.exitIsolation`.
+  `object.isolate {id}` (a group, a layer or a single object; not type) / `object.exitIsolation`.
 - **Dialogs and panel state** (control channel and the app's MCP): `ui.layerOptions {ids?}` and `ui.newLayer
   {sublayer?}` open Layer Options (dialog `layerOptions`: name, color, template, locked, visible, printable, preview,
   dimImages, dimPercent; OK is one undo step), `ui.layersPanelOptions` opens Panel Options (`layersPanelOptions`:
@@ -1572,7 +1572,8 @@ The Selection & Anchor Display and General preferences apply to `pointer_gesture
 - `ctrlClickSelectsBehind` (on by default): a Selection tool click with `mods: {cmd: true}` (Command on macOS, Ctrl
   elsewhere) selects the object under the selected one there, the next such click the one under that, then the
   topmost again. Cmd held to borrow the selection tool from another tool clicks as usual.
-- `doubleClickToIsolate` (on by default): off, a `doubleclick` on a group with the Selection tool no longer isolates it.
+- `doubleClickToIsolate` (on by default): a `doubleclick` with the Selection tool isolates a group, a compound path or a
+  single path, image, mesh or placed file (not type, blends, envelopes, repeats or symbol instances); off, it no longer does.
 - `usePreciseCursors`: the Pen, Eyedropper, Slice and Blend tools' pointers are a crosshair.
 - `snapToPointTolerance` (1–8 px, 2 by default): with View › Snap to Point on and Smart Guides off (desktop app), the
   point a selection is dragged by, a drawn point and a transform tool's reference point land on an anchor or a ruler

docs/ui-parity.md

@@ -74,7 +74,7 @@ tools, never checked side by side) isn't captured row by row.
 | Cut path at selected anchors, Remove Anchor Points, Delete removes segments | done | #1278: segment Delete preserves neighboring edges and endpoint anchors; a second Delete removes the remainder; explicit anchor Delete retains its behavior |
 | Live Corners widgets (radius readout, Alt-click cycles kind, double-click the Corners dialog) | done | a Direct Selection click on a widget selects its corner (#1239); a press-and-drag on a widget of a path selected whole still rounds every corner (#908), and adding widgets to the selection by Shift-click (#1232) is missing |
 | Corners between curved sides (#1144), Relative rounding | partial | Relative rounding missing |
-| Isolation mode by double-click, breadcrumbs, Esc to exit | done | |
+| Isolation mode by double-click (groups and single objects), breadcrumbs, Esc to exit | done | Single paths, compound paths, images, meshes and placed files isolate too ([helpx: Isolate objects](https://helpx.adobe.com/africa/illustrator/desktop/manage-objects/select-objects/isolate-objects.html)) |
 | "Magnetic" moves of selected anchors with a modifier (#955 request) | missing | not an Illustrator feature as documented; under discussion |
 
 ## Smart guides and snapping
@@ -205,6 +205,7 @@ re-measure of the panels added since.
 | 2026-10-12 | minor | Attributes: directly selected compound members read and change the compound fill rule; path direction stays member-local (#1197); score unchanged |
 | 2026-10-12 | minor | Pathfinder Divide: open cutting lines split filled paths with one Undo (#1307); scores and hours unchanged |
 | 2026-10-12 | minor | Numeric entry: click-to-focus selection waits for release so text drags keep their start (#1326, in part); keyboard focus, double-click, arrows and wheel preserved; scores and hours unchanged; short movements below the click threshold remain open |
+| 2026-10-12 | minor | Double Click To Isolate: the Selection tool also isolates a single path, compound path, image, mesh or placed file; only it is hit, marqueed and selected inside; scores and hours unchanged |
 | 2026-10-11 | minor | A marquee inside a filled shape no longer selects it: only touching its path does (#1103); score unchanged (estimated) |
 | 2026-10-11 | minor | Live Corners: corners between curved sides round too, the curve trimmed to what the cut leaves (#1144); score unchanged (estimated) |
 | 2026-10-11 | minor | Artboards: Shift-click selects several, which move, copy and delete together (#1139); score unchanged (estimated) |