Implement NotifyOnStatusChange feature for nodes and enhance Telegram notifications

- Added `NotifyOnStatusChange` property to the `Node` class and related DTOs to allow individual node configuration for status change notifications.
- Updated `NodeHealthCheckService` to send Telegram notifications to admins when a node's status changes, based on the new property.
- Enhanced the `ITelegramNotifier` interface with a method for notifying admins about node status changes.
- Modified the frontend to include a checkbox for `NotifyOnStatusChange` in the node editing dialog, allowing admins to easily configure this setting.
- Updated API documentation to reflect the new `notifyOnStatusChange` parameter in the node update endpoint.
- Added tests to ensure the correct behavior of the new feature and its integration with existing functionality.

backend/src/PnvPanel.Infrastructure/BackgroundJobs/NodeHealthCheckService.cs

@@ -37,6 +37,7 @@ public sealed class NodeHealthCheckService(
         var dbContext = scope.ServiceProvider.GetRequiredService<AppDbContext>();
         var gateway = scope.ServiceProvider.GetRequiredService<IXuiPanelGateway>();
         var notifier = scope.ServiceProvider.GetRequiredService<IRealtimeNotifier>();
+        var telegramNotifier = scope.ServiceProvider.GetRequiredService<ITelegramNotifier>();
 
         var nodes = await dbContext.Nodes.Where(n => n.IsEnabled).ToListAsync(cancellationToken);
 
@@ -54,6 +55,16 @@ public sealed class NodeHealthCheckService(
                     node.LastSyncAt,
                     cancellationToken
                 );
+
+                if (node.NotifyOnStatusChange)
+                {
+                    await telegramNotifier.NotifyAdminsNodeStatusChangedAsync(
+                        node.Id,
+                        node.Name,
+                        newStatus,
+                        cancellationToken
+                    );
+                }
             }
         }
 

backend/src/PnvPanel.Infrastructure/Persistence/Migrations/20260723080059_AddNodeNotifyOnStatusChange.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace PnvPanel.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddNodeNotifyOnStatusChange : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "NotifyOnStatusChange",
+                table: "Nodes",
+                type: "boolean",
+                nullable: false,
+                defaultValue: false);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "NotifyOnStatusChange",
+                table: "Nodes");
+        }
+    }
+}

backend/src/PnvPanel.Infrastructure/Persistence/Migrations/AppDbContextModelSnapshot.cs

@@ -17,7 +17,7 @@ namespace PnvPanel.Infrastructure.Persistence.Migrations
         {
 #pragma warning disable 612, 618
             modelBuilder
-                .HasAnnotation("ProductVersion", "10.0.9")
+                .HasAnnotation("ProductVersion", "10.0.10")
                 .HasAnnotation("Relational:MaxIdentifierLength", 63);
 
             NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
@@ -577,6 +577,9 @@ namespace PnvPanel.Infrastructure.Persistence.Migrations
                         .HasMaxLength(100)
                         .HasColumnType("character varying(100)");
 
+                    b.Property<bool>("NotifyOnStatusChange")
+                        .HasColumnType("boolean");
+
                     b.Property<string>("Status")
                         .IsRequired()
                         .HasMaxLength(32)