docs(skillfs): add lightweight and detailed user guides

[kongche-jbw]

Summary

Add user-facing SkillFS documentation with a lightweight entry guide and a
detailed component reference.

What Changed

• Add docs/skillfs/skillfs.md as the short user guide.

  • Explains what SkillFS is.
  • Covers normal mount, in-place mount, common parameters, and quick checks.
  • Links to the detailed SkillFS reference for advanced usage.

• Add src/skillfs/docs/user-guide.md as the full reference.

  • Covers view semantics, activation file mode, notify socket, reload,
    control socket, trusted writer, install protocols, and config examples.
  • Documents both production activation/control-socket mode and
    decision-command compatibility mode.
  • Keeps activation file semantics accurate: activation JSON expresses
    fallback snapshot or hidden; current is not written through activation JSON.

Behavior / Compatibility

• Documentation-only change.
• No runtime behavior, CLI behavior, or test behavior changes.
• Source-build examples explicitly use the src/skillfs workspace path.
• Security integration docs avoid mixing mutually exclusive modes.

Validation

• git diff --check
• cd src/skillfs && cargo +1.86.0 fmt --all --check

[kongche-jbw]

@1570005763 已处理这几处文档问题：

1. 明确区分 normal mount 和 in-place mount 的访问路径：
   normal mount 是 /skills/，in-place mount 是 /。
2. 修正 in-place 验证命令，不再写成 /skills/。
3. OpenClaw/ClawHub 示例补充 .clawhub/** post-publish 白名单。
4. trusted writer / trusted peer 说明改为“最终执行进程 exe”，避免把 shell wrapper 路径写成可信 exe。
5. 修复 docs/skillfs/skillfs.md 到 user-guide.md 的相对链接。
6. 新增 OpenClaw in-place + Skill Ledger 推荐启动命令和 TOML 示例。

已推送 commit: 29a3716。

[yummypeng]

这两份文档要搞成一模一样的标题吗？ 是不是一个改成 SkillFS 快速入门 之类的？

[1570005763]

@kongche-jbw LGTM. The issues I raised have been addressed in 29a3716.

[yummypeng]

LGTM