[EPIC 7.0] Privacy & DeFi Features


## Problem

Privacy features (Railgun, stealth addresses) and native swap functionality needed.

## Success Criteria

- [ ] Stealth addresses (EIP-5564/6538)
- [ ] Railgun integration
- [ ] Native swap functionality
- [ ] Opt-in fee mechanism

## Non-goals

Running own DEX, custody of swap fees, mandatory fees

## Timeline

Q2 2026 - Q3 2026

## Dependencies

**BLOCKED BY:** Epic 2