feat(timeline): 支持角色轨迹关键帧与轨道拖拽排序

src/editor/canvas/SceneRoot.test.tsx

@@ -4,6 +4,7 @@ import { afterEach, beforeEach, vi } from "vitest";
 import { VIEWPORT_CAMERA_VISUAL_SCALE } from "../schema/cameraGeometry";
 import { degreesRotationToRadians } from "../schema/directorProject";
 import { createInitialDirectorState, useDirectorStore } from "../store/directorStore";
+import { usePlaybackStore } from "../runtime/playbackStore";
 import { getImportedModelNormalization, getTrajectoryGroundPoint, SceneRoot } from "./SceneRoot";
 import { AXIS_COLORS } from "./sceneAxes";
 import { GROUND_GRID_ELEVATION, GROUND_PLANE_SIZE } from "./sceneGround";
@@ -162,6 +163,7 @@ vi.mock("../runtime/CharacterModel", async () => {
 beforeEach(() => {
   vi.spyOn(console, "error").mockImplementation(() => {});
   mockCharacterModelShouldSuspend.current = false;
+  usePlaybackStore.setState({ isPlaying: false, playhead: 0, duration: 5, editingObjectId: null });
   const base = createInitialDirectorState();
   useDirectorStore.setState({
     ...useDirectorStore.getState(),
@@ -678,6 +680,17 @@ it("renders solid trajectory spheres and a smooth curve through the waypoints",
   expect(container.querySelectorAll('mesh[name^="trajectory-point-"]')).toHaveLength(2);
 });
 
+it("puts a walking character at its trajectory sample for the current playhead", () => {
+  useDirectorStore.getState().addTrajectoryPoint("char_default_a", [8, 0, 0]);
+  // 单点轨迹：0s 在角色起始位置，时间轴末尾（5s）到达该轨迹点
+  usePlaybackStore.setState({ isPlaying: false, playhead: 5, duration: 5, editingObjectId: null });
+
+  render(<SceneRoot />);
+
+  const characterGroup = screen.getByTestId("mock-character-model").closest("group");
+  expect(characterGroup).toHaveAttribute("position", "8,0,0");
+});
+
 it("shows a translate gizmo on the selected trajectory point so it can be dragged", () => {
   useDirectorStore.getState().addTrajectoryPoint("char_default_a", [1, 0, 2]);
   const pointId = useDirectorStore