[Access] Data providers should wrap context.Canceled error

[illia-malachyn]

When an issue occurs with a streamer or subscription, and the associated context is canceled, data providers return a context.Canceled error to the WebSocket controller. This is unintended because context.Canceled should only originate from the controller itself.

As a result, user subscriptions may silently shut down without any explicit error or notice, making it difficult to diagnose the issue.

Expected Behavior

• Data providers should verify the actual error returned by the subscription or streamer.
• If the error is context.Canceled, they should wrap it in a more meaningful error before passing it to the WebSocket controller.

This ensures that cancellations triggered internally are distinguishable from those initiated by the controller, preventing silent failures.