* feat(cli): add install scripts for macOS, Linux, and Windows
Bash script (install.sh) for macOS/Linux and PowerShell script
(install.ps1) for Windows. Both download the correct platform binary
from GitHub Releases with checksum verification, version resolution,
and PATH setup.
* fix(cli): address PR review comments for install scripts
- Add checksum verification to install.ps1 using Get-FileHash
- Add warnings on all checksum skip paths in install.sh
- Use grep -F (fixed-string) instead of regex for filename matching
- Add ?per_page=100 to GitHub API call in install.ps1
- Use random temp directory name in install.ps1 to avoid collisions
* fix(cli): address installer review feedback