v0.4.2

Changes

• Keep fullscreen Mermaid viewer controls below the DSH Desktop titlebar on Windows.
• Localize the GitHub-source installer in English and Simplified Chinese, including profile-specific restart guidance.
• Show a localized error when dsh is missing, and use the system language when locale environment values are neutral.

Verification

• Windows CI and all 19 project tests passed.
• npm package and GitHub release archive were built from v0.4.2.

Full changelog: v0.4.1...v0.4.2