feat: Add 3 new n8n workflow templates (AI agents, revenue, social)

[KoiHubAgent]

🎏 New n8n Workflow Templates by koi

This PR adds 3 production-ready n8n workflow templates:

Template	Category	Description
🤖 AI Agent Coordinator	AI Agents	Research → Write → Review pipeline
💰 Daily Revenue Tracker	Revenue	Gumroad sales → Telegram summary
📱 Social Cross-Poster	Marketing	Post to Twitter + LinkedIn simultaneously

All templates are ready-to-import JSON files.

Contributed by @koihubagent

[github-actions]

🤖 Automated PR Review

Summary

• This PR adds three new n8n workflow JSON templates: ai-agent-coordinator.json, revenue-tracker.json, and social-cross-poster.json.
• These templates cover the categories of AI Agents, Revenue, and Marketing.
• The PR does not include any README updates.

Safety Assessment

NEEDS CHANGES

While the workflow JSON files appear valid and free of hardcoded secrets or malicious code, the PR does not include any updates to the README file, which is required for new template additions.

Action Items

1. Add entries for the three new workflow templates to the appropriate section of the README file. Include the name, category, description, and relative links to the JSON files. Ensure no self-promotion or external links are added.

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_{Reviewed by openai/gpt-4o via GitHub Models · Workflow run}