fix: propagate reactor context up till transport

Author: FH-30

mcp/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java

@@ -225,18 +225,19 @@ private String generateRequestId() {
 	public <T> Mono<T> sendRequest(String method, Object requestParams, TypeReference<T> typeRef) {
 		String requestId = this.generateRequestId();
 
-		return Mono.<McpSchema.JSONRPCResponse>create(sink -> {
+		return Mono.deferContextual(ctx -> Mono.<McpSchema.JSONRPCResponse>create(sink -> {
 			this.pendingResponses.put(requestId, sink);
 			McpSchema.JSONRPCRequest jsonrpcRequest = new McpSchema.JSONRPCRequest(McpSchema.JSONRPC_VERSION, method,
 					requestId, requestParams);
 			this.transport.sendMessage(jsonrpcRequest)
-				// TODO: It's most efficient to create a dedicated Subscriber here
-				.subscribe(v -> {
-				}, error -> {
-					this.pendingResponses.remove(requestId);
-					sink.error(error);
-				});
-		}).timeout(this.requestTimeout).handle((jsonRpcResponse, sink) -> {
+					.contextWrite(ctx)
+					// TODO: It's most efficient to create a dedicated Subscriber here
+					.subscribe(v -> {
+					}, error -> {
+						this.pendingResponses.remove(requestId);
+						sink.error(error);
+					});
+		})).timeout(this.requestTimeout).handle((jsonRpcResponse, sink) -> {
 			if (jsonRpcResponse.error() != null) {
 				sink.error(new McpError(jsonRpcResponse.error()));
 			}