Problem

In StreamableHTTPTransport.handle_get_stream, when an SSE stream disconnects or closes (server-side EOF/backpressure), attempt was reset to 0 upon exit. If an upstream server disconnects continuously, the client bypasses MAX_RECONNECTION_ATTEMPTS and enters an infinite reconnection loop without backoff jitter.

Expected Behavior

The client should respect MAX_RECONNECTION_ATTEMPTS on stream disconnects and apply exponential backoff to prevent thundering-herd storms on upstream MCP servers.