Add IP information API with background WHOIS fetcher

- Add /ip and /ip/{addr} JSON endpoints returning comprehensive IP info
- Include ASN, netblock, country code, org name, abuse contact, RIR data
- Extend ASN schema with WHOIS fields (country, org, abuse contact, etc)
- Create background WHOIS fetcher for rate-limited ASN info updates
- Store raw WHOIS responses for debugging and data preservation
- Queue on-demand WHOIS lookups when stale data is requested
- Refactor handleIPInfo to serve all IP endpoints consistently

internal/metrics/metrics.go

@@ -102,14 +102,14 @@ func (t *Tracker) GetStreamMetrics() StreamMetrics {
 	}
 
 	return StreamMetrics{
-		TotalMessages:   totalMessages,
-		TotalBytes:      totalBytes,
-		TotalWireBytes:  totalWireBytes,
-		ConnectedSince:  connectedSince,
-		Connected:       t.isConnected.Load(),
-		MessagesPerSec:  t.messageRate.Rate1(),
-		BitsPerSec:      t.byteRate.Rate1() * bitsPerByte,
-		WireBitsPerSec:  t.wireByteRate.Rate1() * bitsPerByte,
+		TotalMessages:  totalMessages,
+		TotalBytes:     totalBytes,
+		TotalWireBytes: totalWireBytes,
+		ConnectedSince: connectedSince,
+		Connected:      t.isConnected.Load(),
+		MessagesPerSec: t.messageRate.Rate1(),
+		BitsPerSec:     t.byteRate.Rate1() * bitsPerByte,
+		WireBitsPerSec: t.wireByteRate.Rate1() * bitsPerByte,
 	}
 }