- keyframed state, count, read (time in sequence timebase + mapped
values), add/remove, easing read/write (linear/bezier/hold with
control points), and clear - all undoable with full undo/redo
assertions
- easing set commands are minimal capi-local UndoCommands matching
the app-layer semantics (engine has none of its own); same-time
duplicates are rejected with E_STATE instead of hitting the engine's
debug assert
- project node enumeration, type/name/label metadata, input
introspection (id, mapped value type, connection state)
- typed parameter read/write for the eight common NodeValue kinds
(int/float/bool/rational/color/vec2-4/combo/string), undoable via
NodeParamSetSplitStandardValueCommand - the split-track value path,
chosen after proving the standard-value command stores whole
variants into a single component track
- graph operations (add/remove/connect/disconnect) reusing the
engine's undo commands, all covered by undo/redo assertions