Null layers: the Video switch hides them in the Composition viewer, as in After Effects

Every layer gets the Video switch (eye) in the Timeline (nulls, cameras and lights
were excluded by an is_av() check). A selected layer whose eye is off no longer
draws its box, handles, anchor or paths in the viewer. Alt-click on an eye and
Layer > Switches > Hide Other Video now take nulls along.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

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 |
+| 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) |
 | 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 |