feat: implement cross-shard liquidity borrowing in lending protocol

[DeVikingMark]

Short Summary

Implements cross-shard liquidity borrowing functionality allowing users to borrow tokens from lending pools across different shards when their local shard has insufficient liquidity.

What Changes Were Made

• Added lending pool deployment across all 4 shards instead of single shard
• Implemented cross-shard liquidity checking mechanism to query available funds across shards
• Added checkLiquidity() function for inter-shard liquidity verification
• Added transferToBorrower() function for cross-shard token transfers
• Implemented registerLendingPools() to establish cross-shard communication
• Updated lending flow to automatically fallback to cross-shard borrowing when local liquidity is insufficient
• Modified deployment script to deploy and register lending pools across all shards
• Added recursive shard checking logic with proper context handling for async callbacks

Related Issue

Fixes #611

Breaking Changes (if any)

None. The changes are backward compatible and extend existing functionality.

Screenshots / Visual Changes

N/A - Backend smart contract functionality only.

Checklist

• I have read and followed the Contributing Guide
• I have tested the changes locally
• I have added relevant tests (if applicable)
• I have updated documentation/comments (if applicable)