fix(cli): document exact install inputs

[harlan-zw]

❓ Type of change

• 📖 Documentation
• 🐞 Bug fix
• 👌 Enhancement
• ✨ New feature
• 🧹 Chore
• ⚠️ Breaking change

📚 Description

skilld install --help made Agents infer source syntax, Git refs, target names, and modes.

It lists the accepted inputs and defaults now, including locked commit restore. Source errors include a command the Agent can run.

🤖 AI disclosure: Harlan Agent Kit modified this description. My AI open-source policy.

[harlan-zw]

Checked by hand, since CI cannot cover it:

• The README direct command installed Skill skilld from public GitHub.

[harlan-zw]

🤖 READY · 96/100

Harlan Agent Kit posted this automated review. AI open source policy. Last updated: 2026-08-21 05:03 UTC.

• GitHub branch, tag, commit, and tree selectors match the parser.
• Locked verified sources restore the exact Git commit.
• Direct recovery gives each Agent an accurate next action.
• Public CLI tests cover help and each direct recovery path.