docs: the Timeline row controls act on the selection (#1849)

One bullet in the Timeline section of docs/agents.md and a note on the
ui-parity Timeline row, next to the other multi-selection fixes.

docs/agents.md

@@ -595,6 +595,12 @@ Extension points and the bundled extensions: [plugins.md](plugins.md).
   properties, FF missing effects, EE Expressions, LL Waveform, UU everything changed from its
   default. Shift+key adds or removes a set; the same key again hides it; Ctrl/Cmd+` twirls the
   selected layers open or closed. With no layer selected they apply to every layer.
+* A row control clicked on one of several selected layers applies to every selected layer, as in
+  After Effects: the A/V switches (video, audio, solo, lock), the Switches column (shy, collapse,
+  quality, fx, frame blending, motion blur, adjustment, 3D), the label swatch and the Modes column
+  (blending mode, Preserve Transparency), one undo step, with the layers the switch doesn't apply
+  to left out. A control on an unselected row changes that layer alone; Alt-clicking an A/V feature
+  still sets the selected layers apart from the rest.
 * `keys.toggleTransform {"layers"?: [...], "prop": "position"}` (Alt+Shift+A/P/S/R/T) adds or
   removes a keyframe at the current time on that Transform property of each layer, in one undo
   step (separated X/Y/Z Position; Orientation and X/Y/Z Rotation on 3D layers).

docs/ui-parity.md

@@ -17,7 +17,7 @@ feel and platform differences, and the 26.x interface changes are not in yet.
 |---|---|---:|---|
 | Menu bar | After Effects' menus, order, submenus and labels; native on macOS; keyboard-operable in-window bar | 95% | 587 entries in `crates/engine/src/menus.rs`; Adobe-service entries omitted by design; `ui_menus` tests (#279) |
 | Panels and workspaces | Every After Effects panel; all standard workspaces; drag-to-dock, tabs, floating panels, maximise | 75% | `ui_tabs`, `ui_panels`; panels move into their own native windows on any screen (#486 open: no dragging tabs between those windows); #302, #301 and #320 (docking, stacked-panel headers, workspace persistence) are closed |
-| Timeline | Switches, modes, parent & link, twirl-downs, reveal shortcuts (U, UU, P, S, R, T, A, E, M, F, Alt+Shift…), pick whips, graph editor, work area, markers | 75% | `ui_keyframes`, `ui_timeline_*`; expand precomps in place (#601); #456, #457, #569 and #355 (Graph Editor jitter and buttons, negative rotation, bulk keyframing) are closed; Proportional Scrubbing (26.2: Ctrl+Alt / Cmd+Opt scrub of hot text spreads the change over the selected layers by selection order, #770) matched for layers selected as a whole, not yet for individually selected properties; every layer has the Video switch, nulls, cameras and lights included (a null with its eye off has no box or handles in the viewer and isn't picked there) |
+| Timeline | Switches, modes, parent & link, twirl-downs, reveal shortcuts (U, UU, P, S, R, T, A, E, M, F, Alt+Shift…), pick whips, graph editor, work area, markers | 75% | `ui_keyframes`, `ui_timeline_*`; expand precomps in place (#601); #456, #457, #569 and #355 (Graph Editor jitter and buttons, negative rotation, bulk keyframing) are closed; Proportional Scrubbing (26.2: Ctrl+Alt / Cmd+Opt scrub of hot text spreads the change over the selected layers by selection order, #770) matched for layers selected as a whole, not yet for individually selected properties; every layer has the Video switch, nulls, cameras and lights included (a null with its eye off has no box or handles in the viewer and isn't picked there); a row control (a switch, the label swatch, a Modes cell) clicked on one of several selected layers acts on the whole selection, with the layers the switch doesn't apply to left out (#1849) |
 | Composition viewer | Selection, handles with direction-aware cursors, rulers, guides, grids, snapping, channels, exposure, region of interest, snapshots, 3D views, Spacebar hand | 70% | `ui_viewer`, `ui_viewers`; Cmd/Ctrl +/− doesn't zoom (#570); anchor point grab on Linux (#492); #352 (snapping) is closed; no 3D transform gizmos (#392, #347); percentage guides (26.5) exist as View ▸ Add Percentage Guide and Convert Guides to Percentage / Pixels (a guide stores a percent of the comp, so it follows comp-size changes; behaviour inferred from the release note, not compared with After Effects); Copy Frame to Clipboard (26.3) is in the Composition menu and the viewer's context menu |
 | Tools panel | All After Effects tools; long-press flyouts; Tool Creates Shape / Mask; Fill / Stroke options | 80% | #213, #227 fixed; #553 (pen and vertex tools on motion paths) is closed |
 | Nudging and modifiers | Arrow nudge (1 px, Shift 10 px), Alt/Option duplicates and slips, Shift constrains | 75% | #290 nudging fixed; #491 (Linux multi-layer edits) is closed |