improve container network stats granularity by using bytes instead of MB

Changes container network statistics to use raw byte values instead of converting to megabytes agent-side, providing more accurate measurements for low-bandwidth containers. Maintains backward compatibility with older agents/hubs through fallback logic.

- Agent now sends Bandwidth field as [sent_bytes, recv_bytes] array
- Deprecated NetworkSent/NetworkRecv fields still populated for compatibility
- Hub and frontend fall back to deprecated fields when Bandwidth is zero
- Record averaging correctly handles both old and new formats
- TODO markers added for cleanup in version 0.19+

internal/records/records.go

@@ -461,19 +461,24 @@ func (rm *RecordManager) AverageContainerStats(db dbx.Builder, records RecordIds
 			}
 			sums[stat.Name].Cpu += stat.Cpu
 			sums[stat.Name].Mem += stat.Mem
-			sums[stat.Name].NetworkSent += stat.NetworkSent
-			sums[stat.Name].NetworkRecv += stat.NetworkRecv
+			sentBytes := stat.Bandwidth[0]
+			recvBytes := stat.Bandwidth[1]
+			if sentBytes == 0 && recvBytes == 0 && (stat.NetworkSent != 0 || stat.NetworkRecv != 0) {
+				sentBytes = uint64(stat.NetworkSent * 1024 * 1024)
+				recvBytes = uint64(stat.NetworkRecv * 1024 * 1024)
+			}
+			sums[stat.Name].Bandwidth[0] += sentBytes
+			sums[stat.Name].Bandwidth[1] += recvBytes
 		}
 	}
 
 	result := make([]container.Stats, 0, len(sums))
 	for _, value := range sums {
 		result = append(result, container.Stats{
-			Name:        value.Name,
-			Cpu:         twoDecimals(value.Cpu / count),
-			Mem:         twoDecimals(value.Mem / count),
-			NetworkSent: twoDecimals(value.NetworkSent / count),
-			NetworkRecv: twoDecimals(value.NetworkRecv / count),
+			Name:      value.Name,
+			Cpu:       twoDecimals(value.Cpu / count),
+			Mem:       twoDecimals(value.Mem / count),
+			Bandwidth: [2]uint64{uint64(float64(value.Bandwidth[0]) / count), uint64(float64(value.Bandwidth[1]) / count)},
 		})
 	}
 	return result