Implement lending pool fee tier system with loyalty discounts

[Smartdevs17]

Context

Fees need tiering with loyalty discounts.

Current Limitation

Fees are flat with no loyalty rewards.

Expected Outcome

• Fee tier system
• Loyalty discount mechanism
• Fee analytics
• Fee configuration

Acceptance Criteria

• Fee tier system
• Loyalty discount mechanism
• Fee analytics
• Fee configuration
• Fee transparency
• Fee API
• Fee documentation