fix(tui): increase history buffer to 60 so sparkline fills completely

internal/monitor/history.go

@@ -2,7 +2,7 @@ package monitor
 
 import "time"
 
-const maxHistoryLen = 30
+const maxHistoryLen = 60
 
 type SiteHistory struct {
 	Latencies   []time.Duration

internal/tui/tab_sites.go

@@ -211,8 +211,8 @@ func (m Model) dynamicWidths() (nameW, sparkW int) {
 	if sparkW < 10 {
 		sparkW = 10
 	}
-	if sparkW > 40 {
-		sparkW = 40
+	if sparkW > 60 {
+		sparkW = 60
 	}
 	return
 }