Replace live_routes database table with in-memory routing table

- Remove live_routes table from SQL schema and all related indexes
- Create new internal/routingtable package with thread-safe RoutingTable
- Implement RouteKey-based indexing with secondary indexes for efficient lookups
- Add RoutingTableHandler to manage in-memory routes separately from database
- Update DatabaseHandler to only handle persistent database operations
- Wire up RoutingTable through fx dependency injection
- Update server to get live route count from routing table instead of database
- Remove LiveRoutes field from database.Stats struct
- Update tests to work with new architecture

internal/database/models.go

@@ -43,15 +43,3 @@ type ASNPeering struct {
 	FirstSeen time.Time `json:"first_seen"`
 	LastSeen  time.Time `json:"last_seen"`
 }
-
-// LiveRoute represents the current state of a route in the live routing table
-type LiveRoute struct {
-	ID          uuid.UUID  `json:"id"`
-	PrefixID    uuid.UUID  `json:"prefix_id"`
-	OriginASNID uuid.UUID  `json:"origin_asn_id"`
-	PeerASN     int        `json:"peer_asn"`
-	Path        string     `json:"path"`
-	NextHop     string     `json:"next_hop"`
-	AnnouncedAt time.Time  `json:"announced_at"`
-	WithdrawnAt *time.Time `json:"withdrawn_at"`
-}