Top wears the skin; the refresh rate reaches every machine; bug bash 4

The process table's columns fit the box they are in, the rate control saves, curves are
timed on the viewer's clock and keep to the stride, the power icon is drawn, and a young
history draws in from the right instead of being stretched.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/metrics/fold_test.go

@@ -67,3 +67,33 @@ func TestStrideAndTrim(t *testing.T) {
 		t.Errorf("a window past the maximum is the maximum, got %v", c.Window())
 	}
 }
+
+// Points are one stride apart — not a stride and a sample — and jitter doesn't change that.
+func TestKeepSpacing(t *testing.T) {
+	c := &Collector{interval: 2 * time.Second, window: time.Hour} // stride 12 s: six samples a point
+	at := int64(1_000_000)
+	for i := 0; i < 6*40; i++ {
+		jitter := int64((i*37)%41 - 20) // ±20 ms, deterministic
+		c.keep(Sample{T: at + jitter, CPU: float64(i % 6)})
+		at += 2000
+	}
+	if len(c.ring) != 40 {
+		t.Fatalf("240 samples at six a point are 40 points, got %d", len(c.ring))
+	}
+	for i := 1; i < len(c.ring); i++ {
+		if gap := c.ring[i].T - c.ring[i-1].T; gap < 11900 || gap > 12100 {
+			t.Fatalf("point %d is %d ms after the one before; a stride is 12000", i, gap)
+		}
+	}
+	if c.ring[3].CPU != 2.5 {
+		t.Errorf("each point is the mean of its own six samples (0…5 → 2.5), got %v", c.ring[3].CPU)
+	}
+	// and when the stride is the interval, every sample is a point
+	c = &Collector{interval: 2 * time.Second, window: DefaultWindow}
+	for i := 0; i < 50; i++ {
+		c.keep(Sample{T: int64(i)*2000 + int64(i%3) - 1})
+	}
+	if len(c.ring) != 50 {
+		t.Errorf("at the default window every sample is kept, got %d of 50", len(c.ring))
+	}
+}