feat(skills): add dknowc official document writer skill

[zhangzixuan961128-blip]

Summary

This PR adds a new public skill: dknowc-official-doc-writer.

The skill focuses on Chinese official document writing workflows, including:

• policy material retrieval via DKnowC dependable search API
• structured drafting workflow for official documents
• Word export for standard-format documents

Key points

• Added skill path:
  • skills/public/dknowc-official-doc-writer/
• Includes:
  • SKILL.md
  • README.md
  • scripts/ (dkag_search.py, format_document.py, merge_search_results.py)
  • reference/ writing standards and guides
  • config/format.json
  • requirements.txt
• Public DeerFlow-oriented version:
  • no built-in API key
  • users configure their own key in config.ini
  • red-header template generation capability is intentionally removed in this public version

Testing

Validated locally:

1. python3 skills/public/dknowc-official-doc-writer/scripts/dkag_search.py --help
2. python3 skills/public/dknowc-official-doc-writer/scripts/format_document.py --help

Both commands execute successfully.

Notes

• This is a first DeerFlow release style for this skill (v1.0.0 in skill metadata).
• The current public version keeps the scope to searchable drafting + standard Word formatting to minimize binary assets and simplify review.

[CLAassistant]

All committers have signed the CLA.