feat(skills): add Sherlock OSINT username search skill

[unmodeled-tyler]

Summary

Add Sherlock OSINT username search skill to optional-skills for username enumeration across 400+ social networks.

What Changed

• New optional skill: optional-skills/security/sherlock/SKILL.md
• Enables OSINT username enumeration across 400+ social platforms
• Uses Sherlock Project CLI tool (https://github.com/sherlock-project/sherlock)

Features

• Smart username extraction - no clarify prompt when username is obvious in message
• Installation verification before execution
• Clean categorized output with clickable links (social, dev, gaming, etc.)
• Ethical use guidelines included
• Works on all platforms (Linux/macOS/Windows)

How to Test

1. Install sherlock: pipx install sherlock-project
2. Install skill: hermes skills install sherlock
3. Run: hermes chat -q "Search for username nasa"
4. Verify: Results categorized by platform type, links clickable

Platforms Tested

• Linux (Ubuntu 22.04)

Example Output

Found 201 reported matches for username 'nasa'.

Social / media
- https://www.tiktok.com/@nasa
- https://www.github.com/nasa
- https://www.youtube.com/@nasa
...

Results saved to: nasa.txt

[teknium1]

Merged the Sherlock skill via PR #1671 with authorship preserved. The cli.py formatting changes and Vessel Browser skill were excluded — the formatter noise would have caused massive merge conflicts and the Vessel skill was unrelated to this PR. Thanks @unmodeled-tyler!