Always draw all the way to the right.

This probably makes more sense to people.

static/chart.mjs

@@ -75,6 +75,7 @@ class HistoryChart {
             y = point[1] * this.canvas.height
             this.ctx.lineTo(x, y)
         }
+        this.ctx.lineTo(this.canvas.width, y)
         this.ctx.stroke()
 
         requestAnimationFrame(() => this.draw())