feat(agents): implement content generation agent for bounty outcomes (#5)

[angelTomo9]

Closes #5

Summary of Deliverables

Implements the automated content-generation agent scaffold in src/agents/content-agent.ts to generate viral social copy and case studies upon bounty settlements.

Features & Deliverables

• Multi-Format Content Generation:
  • 🐦 Single Tweet: <= 280 character headline tweet with hashtags and bounty metrics.
  • 🧵 5-Tweet Narrative Thread: Structured breakdown covering problem objective, technical solution, settlement amount, and call-to-action.
  • 📝 Structured Blog Post: In-depth case study highlighting architecture, on-chain payout, and community contribution channels.
• Outreach Database Record: Helper formatOutreachRecord structuring output for insertion into outreach_sent.
• Unit Test Suite: tests/content-agent.test.ts verifying character limits, thread length, and case study section structure.