fix(tui): size NAME column to actual content, surplus goes to sparkline

Compute max monitor name length and cap NAME column to that + 4 (icon/padding).
Extra space goes to HISTORY sparkline instead of dead whitespace.

internal/tui/tab_sites.go

@@ -374,8 +374,19 @@ func (m Model) computeLayout() tableLayout {
 		fixedMin += c.minWidth
 	}
 
+	maxName := 0
+	for _, s := range m.sites {
+		if n := len([]rune(s.Name)); n > maxName {
+			maxName = n
+		}
+	}
+	maxName += 4 // icon + padding + error preview room
+
 	avail := usable - fixedMin
 	nameW := avail / 2
+	if nameW > maxName {
+		nameW = maxName
+	}
 	sparkW := avail - nameW - 2
 
 	if nameW < 13 {