TASK: Create docs/02-agent-development-rules.md

This document defines NON-NEGOTIABLE rules for AI agents.

Must include:
- File creation rules
- Naming conventions
- Where logic is allowed / forbidden
- How to mock Data Connect safely
- How to introduce new features
- How to reuse prototype code without copying architecture mistakes
- Rules for handling ambiguity (must document, not assume)

Format:
- Clear numbered rules
- Short explanations
- Explicit "DO / DO NOT" sections

This document will be enforced strictly.