Fix sandbox container test failure caused by pnpm workspace symlinks

[Copilot]

The Lint, Typecheck, Build & Test workflow was failing in @argus/sandbox because the Docker lifecycle test copied the package working directory (including pnpm symlinked node_modules) into the container. Docker rejected those links with invalid symlink during docker cp.

• Root cause alignment

  • SandboxContainer lifecycle test used workspacePath: process.cwd(), which points at a workspace directory containing pnpm symlinks not portable via docker cp.

• Targeted test fix

  • Updated the container lifecycle test to create and use an isolated temp workspace directory instead of the package cwd.
  • Added explicit cleanup of that temp directory in finally to keep the test hermetic.

• Scope

  • Test-only change in packages/sandbox/test/container.test.ts; no runtime behavior changes.

const workspacePath = await fs.mkdtemp(path.join(os.tmpdir(), "argus-sandbox-test-"));
const container = new SandboxContainer({
  workspacePath,
  timeoutMs: 30000,
});

try {
  await container.initialize();
  // ...
} finally {
  await container.destroy();
  await fs.rm(workspacePath, { recursive: true, force: true });
}