v0.1.1
feat: add frg upgrade command for self-updating
Downloads the latest release binary from GitHub, replaces the current
binary with automatic rollback on failure. Detects OS/arch, uses
curl + tar, sets executable permissions.
Usage: frg upgrade
Output: "Current version: v0.1.0 -> Upgrading to v0.2.0..." or
"Already up to date (v0.1.0)."
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>