forgepulse: the echarts 6 bump moved the legend onto the axis labels

The echarts 5 → 6 bump in forgepulse changed the default legend position from top to bottom, so on both charts the legend collided with the x-axis date labels while the 48px the grid reserves at the top sat empty — legend.top is now set explicitly, so the layout stops depending on a library default (94fb8c1). The same release draws a filled marker on every data point, which on a hundred-day series is clutter; the dots are hidden on all eight series through one shared base while the axis tooltip still marks the hovered point (1f70b65). Both rode in with the vitest 4.1.11 / echarts 6.1.0 security bump.