Major schema refactoring: simplify ASN and prefix tracking

- Remove UUID primary keys from ASNs table, use ASN number as primary key
- Update announcements table to reference ASN numbers directly
- Rename asns.number column to asns.asn for consistency
- Add prefix tracking to PrefixHandler to populate prefixes_v4/v6 tables
- Add UpdatePrefixesBatch method for efficient batch updates
- Update all database methods and models to use new schema
- Fix all references in code to use ASN field instead of Number
- Update test mocks to match new interfaces

internal/server/handlers.go

@@ -605,7 +605,7 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 
 		// Group by origin AS and collect unique AS info
 		type ASNInfo struct {
-			Number      int
+			ASN         int
 			Handle      string
 			Description string
 			PeerCount   int
@@ -622,7 +622,7 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 					description = asInfo.Description
 				}
 				originMap[route.OriginASN] = &ASNInfo{
-					Number:      route.OriginASN,
+					ASN:         route.OriginASN,
 					Handle:      handle,
 					Description: description,
 					PeerCount:   0,
@@ -655,7 +655,7 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 
 		// Create enhanced routes with AS path handles
 		type ASPathEntry struct {
-			Number int
+			ASN    int
 			Handle string
 		}
 		type EnhancedRoute struct {
@@ -674,7 +674,7 @@ func (s *Server) handlePrefixDetail() http.HandlerFunc {
 			for j, asn := range route.ASPath {
 				handle := asinfo.GetHandle(asn)
 				enhancedRoute.ASPathWithHandle[j] = ASPathEntry{
-					Number: asn,
+					ASN:    asn,
 					Handle: handle,
 				}
 			}