Fix Bug modelcontextprotocol#6: Remove blocking await logger calls from response handlers

- Removed await logger?.trace() from handleResponse() (lines 689-692)
- Removed await logger?.trace() from handleMessage() (lines 716-719)
- Removed await logger?.trace() from handleBatchResponse() (lines 762-763)

These calls were causing 10-second actor boundary crossing delays when
processing tool call responses, causing callTool() to appear to hang.

Replaced with NSLog() for immediate, non-blocking logging.

This fixes the final blocker preventing MCP tool execution from working.

Author: dcherrera

Sources/MCP/Client/Client.swift

@@ -686,9 +686,11 @@ public actor Client {
     // MARK: -
 
     private func handleResponse(_ response: Response<AnyMethod>) async {
-        await logger?.trace(
-            "Processing response",
-            metadata: ["id": "\(response.id)"])
+        // REMOVED: await logger?.trace() - causes actor boundary crossing delay
+        // await logger?.trace(
+        //     "Processing response",
+        //     metadata: ["id": "\(response.id)"])
+        NSLog("🔵 CLIENT.handleResponse() for id: \(response.id)")
 
         // Attempt to remove the pending request using the response ID.
         // Resume with the response only if it hadn't yet been removed.
@@ -711,9 +713,11 @@ public actor Client {
     }
 
     private func handleMessage(_ message: Message<AnyNotification>) async {
-        await logger?.trace(
-            "Processing notification",
-            metadata: ["method": "\(message.method)"])
+        // REMOVED: await logger?.trace() - causes actor boundary crossing delay
+        // await logger?.trace(
+        //     "Processing notification",
+        //     metadata: ["method": "\(message.method)"])
+        NSLog("🔵 CLIENT.handleMessage() method: \(message.method)")
 
         // Find notification handlers for this method
         guard let handlers = notificationHandlers[message.method] else { return }
@@ -755,7 +759,9 @@ public actor Client {
 
     // Add handler for batch responses
     private func handleBatchResponse(_ responses: [AnyResponse]) async {
-        await logger?.trace("Processing batch response", metadata: ["count": "\(responses.count)"])
+        // REMOVED: await logger?.trace() - causes actor boundary crossing delay
+        // await logger?.trace("Processing batch response", metadata: ["count": "\(responses.count)"])
+        NSLog("🔵 CLIENT.handleBatchResponse() count: \(responses.count)")
         for response in responses {
             // Attempt to remove the pending request.
             // If successful, pendingRequest contains the request.