【BUG】PermissionMode behaves abnormally on Windows when systemPrompt contains `\n`

[fuzi1996]

When using systemPrompt with a newline character (\n) on Windows, the PermissionMode does not work as expected.

Reproduction Steps

1. Initialize ClaudeSyncClient with PermissionMode.BYPASS_PERMISSIONS

2. Case 1 (Works correctly): Do not set systemPrompt (or set it without \n)

   • Code snippet:

     try (ClaudeSyncClient client = ClaudeClient.sync()
                     .workingDirectory(Path.of("."))
                     .model(MODEL_HAIKU)
                     .permissionMode(PermissionMode.BYPASS_PERMISSIONS)
                     .build()) {
         client.connect("hi");
         Iterator<ParsedMessage> response = client.receiveResponse();
         while (response.hasNext()) {
             ParsedMessage msg = response.next();
             if (msg.isRegularMessage() && msg.asMessage() instanceof SystemMessage system) {
                 String permissionMode = (String) system.data().get("permissionMode");
                 System.out.println(permissionMode);
             }
         }
     } catch (Exception e) {
         // ignore
     }

   • Output: bypassPermissions (expected)

3. Case 2 (Abnormal behavior): Set systemPrompt with \n (e.g., "You are an AI assistant.\n")

   • Code snippet:

     public static void main(String[] args) {
         try (ClaudeSyncClient client = ClaudeClient.sync()
                         .workingDirectory(Path.of("."))
                         .model(MODEL_HAIKU)
                         .systemPrompt("You are an AI assistant.\n")
                         .permissionMode(PermissionMode.BYPASS_PERMISSIONS)
                         .build()) {
             client.connect("hi");
             Iterator<ParsedMessage> response = client.receiveResponse();
             while (response.hasNext()) {
                 ParsedMessage msg = response.next();
                 if (msg.isRegularMessage() && msg.asMessage() instanceof SystemMessage system) {
                     String permissionMode = (String) system.data().get("permissionMode");
                     System.out.println(permissionMode);
                 }
             }
         } catch (Exception e) {
             // ignore
         }
     }

   • Output: default (unexpected, should be bypassPermissions)

Environment

• OS: Windows
• Key issue: The existence of \n in systemPrompt causes PermissionMode to not be applied correctly.