🗺️ Create Project Roadmap

# 🧠 Concept
Provide visibility into Sentinel's future development.

## ⚠️ Problem
Contributors need to understand project direction.

## 📁 Implementation Scope
- ROADMAP.md

## ✅ Requirements
- MVP goals
- Future milestones
- Ecosystem expansion plans

## 🎯 Acceptance Criteria
- [ ] Roadmap created
- [ ] Milestones documented