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/routewatch/app_integration_test.go

@@ -158,6 +158,12 @@ func (m *mockStore) GetActiveLiveRoutes() ([]database.LiveRoute, error) {
 	return []database.LiveRoute{}, nil
 }
 
+// UpdatePeer mock implementation
+func (m *mockStore) UpdatePeer(peerIP string, peerASN int, messageType string, timestamp time.Time) error {
+	// Simple mock - just return nil
+	return nil
+}
+
 // Close mock implementation
 func (m *mockStore) Close() error {
 	return nil