docs: add architecture diagram to README #1
Description
Description
Add an ASCII or Mermaid architecture diagram to README.md showing the internal structure of PicoClaw:
- Message Bus
- Channel system (Telegram, Discord, etc.)
- Agent Loop
- Tool Registry
- Skill system
Acceptance Criteria
- Diagram clearly shows component relationships
- Diagram is rendered correctly on GitHub
Skills needed
Markdown, basic understanding of Go project structure