feat: Add call duration to call detail view

internal/sip/callflow.go

@@ -52,11 +52,18 @@ func (s *CallFlowStore) AddPacket(p *Packet) *CallFlow {
 	}
 
 	flow, exists := s.flows[p.CallID]
+
+	// Determine timestamp to use
+	ts := p.Timestamp
+	if ts.IsZero() {
+		ts = time.Now()
+	}
+
 	if !exists {
 		flow = &CallFlow{
 			CallID:    p.CallID,
 			Packets:   make([]*Packet, 0),
-			StartTime: time.Now(),
+			StartTime: ts,
 			From:      p.From,
 			To:        p.To,
 			State:     CallStateInitial,
@@ -65,7 +72,10 @@ func (s *CallFlowStore) AddPacket(p *Packet) *CallFlow {
 	}
 
 	flow.Packets = append(flow.Packets, p)
-	flow.EndTime = time.Now()
+	// Always update EndTime to the latest packet's timestamp
+	if ts.After(flow.EndTime) {
+		flow.EndTime = ts
+	}
 
 	// Update call state based on packet
 	s.updateState(flow, p)