The v2025.9.0.2 fix only added fallbacks to the scan-triggered install
path. This patch also adds the same fallbacks to the direct
'medusa install <tool>' command:

- Try ecosystem installers (cargo, go) when platform PM unavailable
- Try manual install scripts as last resort on Linux
- Better error messages showing manual install commands

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>