feat: add prefix cache warm-up routine to PrefixService

- Introduce `WarmUpAsync` method to pre-cache prefixes for ASNs and RU-specific routes.
- Update `Program` to execute cache warm-up before starting BGP operations.
- Extend `IPrefixService` interface with `WarmUpAsync`.

BGPLite.Providers/PrefixService.cs

@@ -78,6 +78,38 @@ public sealed class PrefixService : IPrefixService
         return GetPrefixesForAsns(ruAsns);
     }
 
+    public async Task WarmUpAsync()
+    {
+        var lists = _config.RipeStat?.AsnLists ?? [];
+
+        var allAsns = lists.SelectMany(l => l.Asns).Distinct().ToList();
+        foreach (var asn in allAsns)
+        {
+            try
+            {
+                await GetPrefixesAsync(asn);
+                Console.WriteLine($"  WarmUp: AS{asn} cached");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"  WarmUp: AS{asn} failed — {ex.Message}");
+            }
+        }
+
+        if (lists.Any(l => l.Country is not null))
+        {
+            try
+            {
+                var ru = await GetRuPrefixesAsync();
+                Console.WriteLine($"  WarmUp: RU prefixes — {ru.Count} entries");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"  WarmUp: RU prefixes failed — {ex.Message}");
+            }
+        }
+    }
+
     private static IReadOnlyList<(uint Prefix, byte Length)> LoadFromFile(string path)
     {
         var result = new List<(uint Prefix, byte Length)>();

BGPLite.Server/IPrefixService.cs

@@ -6,4 +6,5 @@ public interface IPrefixService
     Task<List<(uint Prefix, byte Length, uint Asn)>> GetPrefixesForAsns(IEnumerable<uint> asns);
     Task<int> GetPrefixCountAsync(uint asn);
     Task<List<(uint Prefix, byte Length, uint Asn)>> GetRuPrefixesAsync();
+    Task WarmUpAsync();
 }

BGPLite/Program.cs

@@ -135,6 +135,12 @@ var logger = host.Services.GetRequiredService<ILogger<Program>>();
 logger.LogInformation("BGPLite starting — ASN={Asn}, RouterId={RouterId}", config.Bgp.Asn, config.Bgp.RouterId);
 logger.LogInformation("Loaded routes: {RouteCount}", routeTable.Count);
 
+// Pre-warm prefix cache before accepting BGP connections
+Console.WriteLine("Warming up prefix cache...");
+var prefixService = host.Services.GetRequiredService<IPrefixService>();
+await prefixService.WarmUpAsync();
+Console.WriteLine("Prefix cache ready");
+
 await host.RunAsync();
 return;