Major improvements: MinIO 4.0.7 compatibility, file handle fixes, clean logging, session management

Key Achievements:
- Downgraded to MinIO 4.0.7 for PowerShell compatibility (eliminated async/await issues)
- Fixed file handle leaks in upload operations (using explicit FileStream management)
- Implemented clean logging (timestamps without redundant prefixes)
- Fixed automatic session variable management (Connect-MinIO stores, cmdlets retrieve)
- Removed duplicate certificate parameters (kept only SkipCertificateValidation)
- Fixed all 'Folder' alias conflicts across cmdlets
- Added correct System.Runtime.CompilerServices.Unsafe.dll version (4.5.3)

 Working Features:
- Connection management (automatic + explicit override)
- Bucket operations (list, create, remove)
- File upload/download (with proper handle release)
- Progress tracking and speed reporting
- Clean verbose logging with timestamps

 Known Issue:
- Chunked operations have threading violations (PowerShell cmdlet methods called from background threads)
- Regular operations work perfectly, chunked operations need threading architecture fix

 Test Results:
- 3.71GB Windows install.wim file tested
- Regular upload/download:  Working
- File handles:  No leaks, immediate deletion possible
- Session management:  Automatic connection storage/retrieval
- Chunked operations:  Threading violations need fix

src/Cmdlets/GetMinIOObjectContentCmdlet.cs

@@ -175,7 +175,10 @@ namespace PSMinIO.Cmdlets
             try
             {
                 var testFile = Path.Combine(FilePath.DirectoryName ?? ".", $".psminiotest_{Guid.NewGuid():N}");
-                File.WriteAllText(testFile, "test");
+                using (var testStream = File.Create(testFile))
+                {
+                    testStream.WriteByte(0);
+                }
                 File.Delete(testFile);
             }
             catch (Exception ex)