With the C ABI facade (oakengine) retired, the frozen-ABI rationale is
gone. UndoCommand now boxes a Send Command trait (new/from_closures/
multi), dropping OakUndoCommandVtable, the userdata trampolines, the
refcount shell, the handle module, and all undostack_* handle exports.
The global facade loses its raw-pointer out-params (can_undo/can_redo
return bool, command_name returns String). oaktimeline/oaknode/
oakplugin/oaktask construct commands directly via UndoCommand::new.
oakundo src is now free of unsafe; behavior (ordering, idempotence,
done flags, groups, observers, 200-row cap) is unchanged and pinned by
the rewritten tests.
- oaktimeline::multicam: clip_find_multicam (buffer/tex_in depth-1
lookup), multicam_enable/disable (rewire sequence<->clip through a
MultiCamNode), multicam_switch (split-preserving-links at the
playhead, each half owns an independent multicam copy, linked clips
switched together) as single undo commands with C++ labels.
- BlockSplitCommand now duplicates the clip's whole dependency graph
(copy_node_and_dependency_graph_minus_items) instead of just the
block core, matching the C++ BlockSplitCommand::prepare semantics;
undo detaches the copied subgraph, redo re-attaches identity-
preserving.
- oaknode: fix serializer dropping edges from the first-created node
(ptr=0 was not registered in id_map), restoring sequence_in edge
round-trips; multicam node and clip wiring serializer round-trip
tests.
Mike-Solar