Function onPointerMove

web/components/GraphView.tsx:666–691

(e: PointerEvent)

    };

    const onPointerMove = (e: PointerEvent) => {
      const { px, py } = toLocal(e);
      // 任意拖动（拖节点 或 空白平移）超过阈值即记为「移动过」→ 松手不算点击，
      // 否则平移空白后会误判成「点空白 → 取消选中」。
      if (pointerDownRef.current) {
        const ddx = px - pointerDownRef.current.x, ddy = py - pointerDownRef.current.y;
        if (ddx * ddx + ddy * ddy > 16) pointerDownRef.current.moved = true;
      }
      const drag = draggingRef.current;
      if (drag) {
        const tf = transformRef.current;
        drag.fx = (px - tf.x) / tf.k;
        drag.fy = (py - tf.y) / tf.k;
        sim.alphaTarget(0.3).restart();
        return;
      }
      const hit = pickNode(px, py);
      const newId = hit ? hit.id : null;
      if (newId !== hoverIdRef.current) {
        hoverIdRef.current = newId;
        canvas.style.cursor = newId ? "pointer" : "grab";
        // 卡片跟随 hover；无 hover 时退回展示「选中」节点的卡
        cardFor(newId ?? selectedIdRef.current);
        draw();
      }
    };

    const onPointerDown = (e: PointerEvent) => {
      const { px, py } = toLocal(e);