feat(runtime): track node lifecycle and QUIC link state

backend/src/MoShiro.Backend.Application/Agents/AgentService.cs

@@ -7,10 +7,46 @@ using MoShiro.Protocol;
 
 namespace MoShiro.Backend.Application;
 
-public sealed record AgentView(AgentRecord Agent, bool Online, IReadOnlyList<ConnectedProbeInfo> Probes, AgentHeartbeatExtra? Heartbeat, int EndpointChanges, long? HeartbeatAtMs = null, HostSnapshot? Host = null)
+public sealed record AgentView(AgentRecord Agent, bool Online, IReadOnlyList<ConnectedProbeInfo> Probes, AgentHeartbeatExtra? Heartbeat, int EndpointChanges, long? HeartbeatAtMs = null, HostSnapshot? Host = null, string? LastDisconnectReason = null)
 {
     /// <summary>至少有一个 Probe 连着。</summary>
     public bool ProbeConnected => Probes.Count > 0;
+
+    public NodeRuntimeStatus RuntimeStatus
+    {
+        get
+        {
+            if (Agent.Status == NodeStatus.Disabled)
+            {
+                return NodeRuntimeStatus.Maintenance;
+            }
+            if (Agent.Status == NodeStatus.Pending)
+            {
+                return NodeRuntimeStatus.Initializing;
+            }
+            if (!Online)
+            {
+                if (LastDisconnectReason == "updating")
+                {
+                    return NodeRuntimeStatus.Updating;
+                }
+                if (LastDisconnectReason == "stopping")
+                {
+                    return Heartbeat?.Update?.State == "applying" ? NodeRuntimeStatus.Updating : NodeRuntimeStatus.Stopping;
+                }
+                return NodeRuntimeStatus.Offline;
+            }
+            if (Heartbeat?.Update?.State == "applying")
+            {
+                return NodeRuntimeStatus.Updating;
+            }
+            if (Heartbeat is null)
+            {
+                return NodeRuntimeStatus.Initializing;
+            }
+            return Heartbeat.RuntimeStatus;
+        }
+    }
 }
 
 /// <summary>Agent 的管理：列表、修改、审批、启停、接管、删除，以及 Probe 需要的 Agent 列表。</summary>
@@ -53,9 +89,12 @@ public sealed partial class AgentService
     public AgentView View(AgentRecord agent)
     {
         _runtime.TryGet(agent.Id, out AgentRuntimeState? state);
-        return new AgentView(agent, _gateway.IsOnline(agent.Id), state?.Probes ?? [], state?.LastHeartbeat, state?.EndpointChanges ?? 0, state?.LastHeartbeatAtMs, state?.Host);
+        return new AgentView(agent, _gateway.IsOnline(agent.Id), state?.Probes ?? [], state?.LastHeartbeat, state?.EndpointChanges ?? 0, state?.LastHeartbeatAtMs, state?.Host, state?.LastDisconnectReason);
     }
 
+    public ValueTask<bool> NotifyProbeLinkRetryAsync(NodeId probe, NodeId agent, CancellationToken ct) =>
+        _gateway.NotifyProbeLinkRetryAsync(probe, agent, ct);
+
     private static bool ValidHost(string host, string ipVersion)
     {
         if (IPAddress.TryParse(host, out IPAddress? address))