Enhance inbound management by removing MaxClients property

- Removed the MaxClients property from Inbound-related data models, including InboundDto and PublishInboundCommand.
- Updated related methods and handlers to reflect the removal of MaxClients, ensuring consistent behavior across the application.
- Adjusted API documentation and frontend components to remove references to MaxClients, streamlining the inbound publishing process.
- Enhanced logging in command handlers to handle node unavailability scenarios during user actions.
- Improved database schema and migrations to align with the updated data model.

backend/tests/PnvPanel.IntegrationTests/Admin/NodeInboundCrudTests.cs

@@ -27,7 +27,6 @@ public class NodeInboundCrudTests(PnvPanelWebApplicationFactory factory)
         int Port,
         bool IsPublished,
         string? DisplayName,
-        int? MaxClients,
         IReadOnlyList<Guid> AllowedRoleIds
     );
 
@@ -83,7 +82,6 @@ public class NodeInboundCrudTests(PnvPanelWebApplicationFactory factory)
                 isPublished = true,
                 displayName = "Germany (VLESS)",
                 allowedRoleIds = Array.Empty<Guid>(),
-                maxClients = (int?)null,
             }
         );
         Assert.Equal(HttpStatusCode.OK, publishResponse.StatusCode);