Fix file retention after updates on macOS #417

This fixes issue #417 where autoupdate installer files were not deleted
on macOS, leading to accumulation of old installers.

Key changes:

- Store update files in application-specific directory
- Clear update files directory on every app launch

Other supporting changes:

- Refactor file system operations to be more testable and reusable
- Improve separation of concerns in directory management
- Enhance dependency injection for auto-update logic
- Fix async completion to support `await` operations
- Add additional logging and revise some log messages during updates

tests/unit/shared/Stubs/SystemOperationsStub.ts

@@ -1,35 +1,17 @@
 import type {
   CommandOps,
-  FileSystemOps,
-  OperatingSystemOps,
-  LocationOps,
   SystemOperations,
 } from '@/infrastructure/CodeRunner/System/SystemOperations';
+import type { FileSystemOperations } from '@/infrastructure/FileSystem/FileSystemOperations';
 import { CommandOpsStub } from './CommandOpsStub';
-import { FileSystemOpsStub } from './FileSystemOpsStub';
-import { LocationOpsStub } from './LocationOpsStub';
-import { OperatingSystemOpsStub } from './OperatingSystemOpsStub';
+import { FileSystemOperationsStub } from './FileSystemOperationsStub';
 
 export class SystemOperationsStub implements SystemOperations {
-  public operatingSystem: OperatingSystemOps = new OperatingSystemOpsStub();
-
-  public location: LocationOps = new LocationOpsStub();
-
-  public fileSystem: FileSystemOps = new FileSystemOpsStub();
+  public fileSystem: FileSystemOperations = new FileSystemOperationsStub();
 
   public command: CommandOps = new CommandOpsStub();
 
-  public withOperatingSystem(operatingSystemOps: OperatingSystemOps): this {
-    this.operatingSystem = operatingSystemOps;
-    return this;
-  }
-
-  public withLocation(location: LocationOps): this {
-    this.location = location;
-    return this;
-  }
-
-  public withFileSystem(fileSystem: FileSystemOps): this {
+  public withFileSystem(fileSystem: FileSystemOperations): this {
     this.fileSystem = fileSystem;
     return this;
   }