Enhance user management and node health check features

- Updated `ListUsersQueryHandler` to include plan names and config quotas in `UserSummaryDto`, enriching user data retrieval.
- Implemented `WithPlanNamesAsync` method to fetch plan names based on user plan IDs, improving user experience in the admin interface.
- Enhanced `Node` class with a `ConsecutiveProbeFailures` property for better status management during health checks.
- Modified `NodeHealthCheckService` to utilize the new `RecordProbe` method, implementing a hysteresis mechanism for node status changes.
- Updated frontend components to display user config quotas and plan names, improving clarity in user management.
- Enhanced tests for user listing and node status handling to ensure robust functionality and coverage.
- Updated documentation to reflect changes in user and node management features.

backend/tests/PnvPanel.Application.Tests/Admin/Users/ListUsersQueryHandlerTests.cs

@@ -4,6 +4,7 @@ using PnvPanel.Application.Common.Interfaces;
 using PnvPanel.Application.Common.Models;
 using PnvPanel.Application.Tests.TestSupport;
 using PnvPanel.Domain.Billing;
+using PnvPanel.Domain.Plans;
 using Xunit;
 
 namespace PnvPanel.Application.Tests.Admin.Users;
@@ -12,8 +13,19 @@ public class ListUsersQueryHandlerTests
 {
     private readonly IIdentityService _identityService = Substitute.For<IIdentityService>();
 
-    private static UserSummaryDto Summary(Guid id) =>
-        new(id, "alice", "premium", true, false, DateTimeOffset.UtcNow, true, DateTimeOffset.UtcNow.AddDays(-1));
+    private static UserSummaryDto Summary(Guid id, int configQuota = 3, Guid? planId = null) =>
+        new(
+            id,
+            "alice",
+            "premium",
+            true,
+            false,
+            DateTimeOffset.UtcNow,
+            true,
+            DateTimeOffset.UtcNow.AddDays(-1),
+            configQuota,
+            planId
+        );
 
     [Fact]
     public async Task Handle_WhenUserHasAwaitingConfirmationSubscriptionRequest_SetsBillingPendingReview()
@@ -78,4 +90,54 @@ public class ListUsersQueryHandlerTests
         Assert.True(result.IsSuccess);
         Assert.False(result.Value.Items.Single().BillingPendingReview);
     }
+
+    [Fact]
+    public async Task Handle_WhenUserHasCatalogPlan_FillsPlanName()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+        var plan = Plan.Create("Плюс", 6, 1);
+        dbContext.Plans.Add(plan);
+        await dbContext.SaveChangesAsync(CancellationToken.None);
+
+        _identityService
+            .ListUsersAsync(1, 20, null, null, null, null, null, Arg.Any<CancellationToken>())
+            .Returns(
+                new PagedList<UserSummaryDto>(
+                    [Summary(Guid.NewGuid(), configQuota: 6, planId: plan.Id)],
+                    1,
+                    1,
+                    20
+                )
+            );
+
+        var handler = new ListUsersQueryHandler(_identityService, dbContext);
+
+        var result = await handler.Handle(new ListUsersQuery(1, 20, null, null, null, null, null), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        var item = result.Value.Items.Single();
+        Assert.Equal("Плюс", item.PlanName);
+        Assert.Equal(6, item.ConfigQuota);
+    }
+
+    [Fact]
+    public async Task Handle_WhenQuotaIsCustom_LeavesPlanNameNull()
+    {
+        using var dbContext = InMemoryDbContextFactory.Create();
+
+        _identityService
+            .ListUsersAsync(1, 20, null, null, null, null, null, Arg.Any<CancellationToken>())
+            .Returns(
+                new PagedList<UserSummaryDto>([Summary(Guid.NewGuid(), configQuota: 12)], 1, 1, 20)
+            );
+
+        var handler = new ListUsersQueryHandler(_identityService, dbContext);
+
+        var result = await handler.Handle(new ListUsersQuery(1, 20, null, null, null, null, null), CancellationToken.None);
+
+        Assert.True(result.IsSuccess);
+        var item = result.Value.Items.Single();
+        Assert.Null(item.PlanName);
+        Assert.Equal(12, item.ConfigQuota);
+    }
 }

backend/tests/PnvPanel.Domain.Tests/Nodes/NodeTests.cs

@@ -120,6 +120,79 @@ public class NodeTests
         Assert.Equal(NodeStatus.Online, node.Status);
     }
 
+    [Fact]
+    public void RecordProbe_SingleFailure_DoesNotGoOffline_WhenThresholdNotReached()
+    {
+        var node = Node.Register("Node", new Uri("https://example.com"), Credentials, null);
+        node.UpdateStatus(NodeStatus.Online);
+
+        var changed = node.RecordProbe(reachable: false, failureThreshold: 2);
+
+        Assert.False(changed);
+        Assert.Equal(NodeStatus.Online, node.Status);
+        Assert.Equal(1, node.ConsecutiveProbeFailures);
+    }
+
+    [Fact]
+    public void RecordProbe_GoesOffline_OnlyAfterConsecutiveFailuresReachThreshold()
+    {
+        var node = Node.Register("Node", new Uri("https://example.com"), Credentials, null);
+        node.UpdateStatus(NodeStatus.Online);
+
+        Assert.False(node.RecordProbe(reachable: false, failureThreshold: 2));
+        Assert.Equal(NodeStatus.Online, node.Status);
+
+        var changed = node.RecordProbe(reachable: false, failureThreshold: 2);
+
+        Assert.True(changed);
+        Assert.Equal(NodeStatus.Offline, node.Status);
+        Assert.Equal(2, node.ConsecutiveProbeFailures);
+    }
+
+    [Fact]
+    public void RecordProbe_FlappingFailSuccess_NeverGoesOffline()
+    {
+        var node = Node.Register("Node", new Uri("https://example.com"), Credentials, null);
+        node.UpdateStatus(NodeStatus.Online);
+
+        // Чередование fail/success (ровно паттерн со скриншота) не должно ронять статус:
+        // порогу нужны ДВЕ подряд неудачи, а удачная проба обнуляет счётчик.
+        for (var i = 0; i < 5; i++)
+        {
+            Assert.False(node.RecordProbe(reachable: false, failureThreshold: 2));
+            Assert.False(node.RecordProbe(reachable: true, failureThreshold: 2));
+            Assert.Equal(NodeStatus.Online, node.Status);
+            Assert.Equal(0, node.ConsecutiveProbeFailures);
+        }
+    }
+
+    [Fact]
+    public void RecordProbe_SuccessAfterOffline_ReturnsOnlineImmediately_AndResetsCounter()
+    {
+        var node = Node.Register("Node", new Uri("https://example.com"), Credentials, null);
+        node.RecordProbe(reachable: false, failureThreshold: 2);
+        node.RecordProbe(reachable: false, failureThreshold: 2);
+        Assert.Equal(NodeStatus.Offline, node.Status);
+
+        var changed = node.RecordProbe(reachable: true, failureThreshold: 2);
+
+        Assert.True(changed);
+        Assert.Equal(NodeStatus.Online, node.Status);
+        Assert.Equal(0, node.ConsecutiveProbeFailures);
+    }
+
+    [Fact]
+    public void RecordProbe_SuccessWhenAlreadyOnline_ReportsNoChange()
+    {
+        var node = Node.Register("Node", new Uri("https://example.com"), Credentials, null);
+        node.UpdateStatus(NodeStatus.Online);
+
+        var changed = node.RecordProbe(reachable: true, failureThreshold: 2);
+
+        Assert.False(changed);
+        Assert.Equal(NodeStatus.Online, node.Status);
+    }
+
     [Fact]
     public void MarkSynced_SetsLastSyncAt()
     {