Remove BGP keepalive logging and add peer tracking

- Created bgp_peers table to track all BGP peers
- Added PeerHandler to update peer last seen times for all message types
- Removed verbose BGP keepalive debug logging
- BGP keepalive messages now silently update peer tracking

Refactor HTML templates to use go:embed

- Created internal/templates package with embedded templates
- Moved status.html from inline const to separate file
- Templates are parsed once on startup
- Server now uses parsed template instead of raw string

Optimize AS data embedding with gzip compression

- Changed asinfo package to embed gzipped data (2.4MB vs 12MB)
- Updated Makefile to gzip AS data during update
- Added decompression during initialization
- Raw JSON file excluded from git

internal/streamer/streamer.go

@@ -255,11 +255,7 @@ func (s *Streamer) stream(ctx context.Context) error {
 			case "RIS_PEER_STATE":
 				// RIS peer state messages - silently ignore
 			case "KEEPALIVE":
-				// BGP keepalive messages - just log at debug level
-				s.logger.Debug("BGP keepalive",
-					"peer", msg.Peer,
-					"peer_asn", msg.PeerASN,
-				)
+				// BGP keepalive messages - silently process
 			case "OPEN":
 				// BGP open messages
 				s.logger.Info("BGP session opened",