fix: make transaction-manager max retries test platform-specific

- Use invalid Windows file path characters on Windows platform
- Use deeply nested non-existent path on Unix platforms
- Ensures test failure condition is met on all platforms

Author: Mearman

src/utils/transaction-manager.test.ts

@@ -355,7 +355,11 @@ describe('TransactionManager', () => {
     it('should respect max retries', async () => {
       const manager = new TransactionManager({ maxRetries: 0 });
 
-      const invalidFile = join('/invalid/path/file.txt');
+      // Use a path that should fail on all platforms - invalid characters
+      const invalidFile = process.platform === 'win32' 
+        ? 'C:\\invalid\\path\\with\\<>:"|?*\\file.txt'  // Invalid Windows characters
+        : '/invalid/non/existent/deeply/nested/path/file.txt';  // Non-existent deep path
+      
       manager.addFileCreate(invalidFile, 'content');
 
       const result = await manager.execute();