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/routewatch/app.go

@@ -43,6 +43,7 @@ type RouteWatch struct {
 	peerHandler    *PeerHandler
 	prefixHandler  *PrefixHandler
 	peeringHandler *PeeringHandler
+	asnFetcher     *ASNFetcher
 }
 
 // New creates a new RouteWatch instance
@@ -109,6 +110,11 @@ func (rw *RouteWatch) Run(ctx context.Context) error {
 		return err
 	}
 
+	// Start ASN WHOIS fetcher for background updates
+	rw.asnFetcher = NewASNFetcher(rw.db, rw.logger.Logger)
+	rw.asnFetcher.Start()
+	rw.server.SetASNFetcher(rw.asnFetcher)
+
 	// Wait for context cancellation
 	<-ctx.Done()
 
@@ -144,6 +150,11 @@ func (rw *RouteWatch) Shutdown() {
 		rw.peeringHandler.Stop()
 	}
 
+	// Stop ASN WHOIS fetcher
+	if rw.asnFetcher != nil {
+		rw.asnFetcher.Stop()
+	}
+
 	// Stop services
 	rw.streamer.Stop()