feat(quic): replace probe UDP data plane with QUIC datagrams

backend/src/MoShiro.Backend.Api/Contracts/AdminDtos.cs

@@ -42,6 +42,7 @@ public sealed record AgentDto(
     string PublicHost,
     int ProbeTcpPort,
     IReadOnlyList<int> ProbeUdpPorts,
+    IReadOnlyList<int> ProbeQuicPorts,
     IReadOnlyList<string> Labels,
     bool PublicVisible,
     IReadOnlyList<string> Kinds,

backend/src/MoShiro.Backend.Api/Contracts/ApiJsonContext.cs

@@ -22,6 +22,7 @@ namespace MoShiro.Backend.Api;
 [JsonSerializable(typeof(DistributionDto))]
 [JsonSerializable(typeof(HeatmapDto))]
 [JsonSerializable(typeof(LineDto))]
+[JsonSerializable(typeof(QuicLineHealthDto))]
 [JsonSerializable(typeof(TestDto))]
 [JsonSerializable(typeof(PageDto<TestDto>))]
 [JsonSerializable(typeof(PageDto<KindDto>))]

backend/src/MoShiro.Backend.Api/Contracts/PublicDtos.cs

@@ -28,7 +28,27 @@ public sealed record OverviewLineDto(
     int EndpointChanges,
     SummaryDto Summary,
     TestSummaryDto? LastTest,
-    string IpVersion = "ipv4");
+    string IpVersion = "ipv4",
+    QuicLineHealthDto? QuicHealth = null);
+
+/// <summary>Latest QUIC session health reported by the Probe; cumulative counters reset when the Probe restarts.</summary>
+public sealed record QuicLineHealthDto(
+    bool Connected,
+    long HandshakeAttempts,
+    long HandshakeSuccesses,
+    long HandshakeFailures,
+    long HandshakeTimeouts,
+    double? HandshakeSuccessRate,
+    double? HandshakeFailureRate,
+    double? HandshakeTimeoutRate,
+    double? HandshakeP95Ms,
+    long HandshakeSampleCount,
+    double? TransportPacketLossRate,
+    ulong? TransportPacketsSent,
+    uint? TransportCongestionEvents,
+    uint? TransportEcnCongestionEvents,
+    ushort? PathMtu,
+    DateTimeOffset At);
 
 public sealed record OverviewDto(string Range, DateTimeOffset From, DateTimeOffset To, string Step, string Source, bool Degraded, IReadOnlyList<OverviewLineDto> Lines);
 
@@ -90,7 +110,8 @@ public sealed record LineDto(
     IReadOnlyList<string> Kinds,
     TestSummaryDto? LastTest,
     string IpVersion = "ipv4",
-    bool Ipv6Available = false);
+    bool Ipv6Available = false,
+    QuicLineHealthDto? QuicHealth = null);
 
 public sealed record DimensionDto(string Id, string Label, double Weight, double? Value, double? Score);