Improve disconnection handling with safe cleanup and logging

[mayuki]

Add a new test for StreamingHub disconnection to verify exception handling during cleanup.

[Copilot]

Pull Request Overview

This PR enhances the StreamingHub disconnection sequence by wrapping cleanup calls in a safe, exception-logging helper and adds a new test to verify that exceptions in OnDisconnected and group disposal are logged and do not prevent cleanup.

• Introduced CleanupSafeAsync calls around OnDisconnected and Group.DisposeAsync in StreamingHub.
• Added StreamingHubThrowOnDisconnectTest (and supporting wrapper) to assert that errors during disconnect are caught, logged, and the pending-task registry is disposed.
• Updated existing tests (UnaryServiceTest, StreamingHubDisconnectionTest) to call factory.Initialize() and removed manual logs.Clear().

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/MagicOnion.Server.Tests/UnaryServiceTest.cs	Added factory.Initialize(); removed manual logs.Clear()
tests/MagicOnion.Server.Tests/StreamingHubThrowOnDisconnectTest.cs	New test validating safe cleanup on disconnect and error logging
tests/MagicOnion.Server.Tests/StreamingHubDisconnectionTest.cs	Added factory.Initialize(); removed manual logs.Clear()
src/MagicOnion.Server/Hubs/StreamingHub.cs	Wrapped OnDisconnected and group disposal in CleanupSafeAsync with logging

Comments suppressed due to low confidence (5)

tests/MagicOnion.Server.Tests/UnaryServiceTest.cs:23

• Removing logs.Clear() may lead to test-state leakage across test runs; consider clearing logs after factory.Initialize() to maintain isolation.

        this.logs = factory.Logs;

tests/MagicOnion.Server.Tests/StreamingHubDisconnectionTest.cs:21

• Without clearing logs, previous test output may persist and cause false positives; re-add logs.Clear() or reset logs after initialization.

        this.logs = factory.Logs;

tests/MagicOnion.Server.Tests/StreamingHubThrowOnDisconnectTest.cs:53

• Using a fixed Task.Delay can introduce test flakiness; consider polling the condition with a timeout or using a synchronization primitive instead.

        await Task.Delay(100);

tests/MagicOnion.Server.Tests/StreamingHubThrowOnDisconnectTest.cs:26

• [nitpick] Using Single will throw if zero or multiple matches are found; consider SingleOrDefault with a null check or First if only one is expected.

                var desc = services.Single(x => x.ServiceType == typeof(IRemoteClientResultPendingTaskRegistry));

src/MagicOnion.Server/Hubs/StreamingHub.cs:164

• [nitpick] Consider adding XML doc comments summarizing that this helper safely invokes cleanup actions and logs any exceptions to aid maintainability.

        static async ValueTask CleanupSafeAsync(Func<StreamingHubBase<THubInterface, TReceiver>, ValueTask> action, StreamingHubBase<THubInterface, TReceiver> hub)