Add live routing table with CIDR mask length tracking

- Added new live_routes table with mask_length column for tracking CIDR prefix lengths
- Updated PrefixHandler to maintain live routing table with additions and deletions
- Added route expiration functionality (5 minute timeout) to in-memory routing table
- Added prefix distribution stats showing count of prefixes by mask length
- Added IPv4/IPv6 prefix distribution cards to status page
- Updated database interface with UpsertLiveRoute, DeleteLiveRoute, and GetPrefixDistribution
- Set all handler queue depths to 50000 for consistency
- Doubled DBHandler batch size to 32000 for better throughput
- Fixed withdrawal handling to delete routes when origin ASN is available

internal/routewatch/app.go

@@ -178,6 +178,9 @@ func (rw *RouteWatch) Shutdown() {
 	// Stop services
 	rw.streamer.Stop()
 
+	// Stop routing table expiration
+	rw.routingTable.Stop()
+
 	// Stop HTTP server with a timeout
 	const serverStopTimeout = 5 * time.Second
 	stopCtx, cancel := context.WithTimeout(context.Background(), serverStopTimeout)