fix(tui): increase LAT/UPTIME min column widths to prevent wrapping

LAT min 5→7 (fits '142ms' + padding), UPTIME min 5→8 (fits '100.0%' + padding).

internal/tui/tab_sites.go

@@ -353,8 +353,8 @@ func (m Model) computeLayout() tableLayout {
 		{"", "", 0, 0}, // NAME (dynamic)
 		{"TYPE", "TYPE", 8, 10},
 		{"STATUS", "STATUS", 8, 10},
-		{"LAT", "LATENCY", 5, 10},
-		{"UP%", "UPTIME", 5, 8},
+		{"LAT", "LATENCY", 7, 10},
+		{"UP%", "UPTIME", 8, 8},
 		{"", "", 0, 0}, // HISTORY (dynamic)
 		{"SSL", "SSL", 5, 7},
 		{"RT", "RETRIES", 5, 9},