Add Stellar DEX liquidity pool management

## Description
Provide UI for managing liquidity pools on Stellar DEX.

## Requirements
- Liquidity pool discovery
- Deposit/withdrawal UI
- Share tracking
- Fee management
- Performance metrics
- Impermanent loss calculator

## Acceptance Criteria
- [ ] Can view all pools
- [ ] Deposits/withdrawals work
- [ ] Shares are tracked
- [ ] Calculator is accurate