feat(tui): add Windows installer and release validation

[hrhrng]

Summary

• add a verified PowerShell installer for Windows x64
• build and validate five native release archives on every pull request: Apple Silicon and Intel macOS, ARM64 and x64 Linux, and Windows x64
• publish Windows ZIP archives with shared SHA256SUMS on tags/manual publish runs
• exercise Windows install, reinstall, executable launch, checksum rejection, and post-release installation
• update the English, Chinese, and TUI READMEs with platform installation and release behavior
• add the repository-native skills/setup-readio skill with explicit Windows download/configuration instructions

Validation

• all five release targets build and run --version and --help
• all five archives have the expected name and exact root contents
• installer resolves a release, verifies SHA-256, and installs the executable
• reinstall is atomic and idempotent
• checksum mismatch refuses installation and leaves no executable
• setup skill is progressively disclosed through references/configuration.md
• setup skill contract enforces Windows guidance and the 10,000-character limit (7,167 characters)
• macOS, Linux, and Windows CI checks are green

Scope note

The packaged Windows executable and installer are covered. Managed local-voice setup still has POSIX-specific runtime assumptions; the READMEs and skill call that out instead of claiming those paths are Windows-validated.