feat(growth): add warm negotiation guidance

[coreyone]

Summary

• Add warm, respectful guidance for negotiation and customer-service interactions.
• Apply Dale Carnegie’s human-relations principles as sincere practice, not as manipulation.
• Update the OpenAI skill metadata and generated Hermes export.

Validation

• Parsed skill frontmatter and agents/openai.yaml with Ruby’s YAML parser; implicit invocation remains enabled.
• python3 scripts/export_hermes_skills.py --check passes for all 75 exported skills.
• git diff --check passes.
• The bundled quick_validate.py could not run because PyYAML is not installed; equivalent YAML/frontmatter checks passed with Ruby.