core: implement share price calculation in liquidity pool

[EmeditWeb]

Problem

The liquidity pool has total_shares and total_deposits
but no mechanism to calculate the actual share price.
This breaks the yield mechanism entirely.

What To Build

1. Add share price calculation
2. Fix deposit() to issue shares at current price
3. Fix withdraw() to calculate USDC from shares
4. Add accumulate_interest()

Files To Touch

• contracts/liquidity-pool-contract/src/lib.rs
• contracts/liquidity-pool-contract/src/types.rs
• contracts/liquidity-pool-contract/src/storage.rs
• contracts/liquidity-pool-contract/src/tests.rs

Acceptance Criteria

• Share price calculated correctly
• New deposits issued at current share price
• Withdrawals return correct USDC amount
• Interest increases share price for all holders
• All arithmetic uses checked operations

Mandatory Checks Before PR

• cargo build passes
• All tests pass
• No integer overflow possible
• PR references this issue

[Vicsygold]

BOSS PLS I NEED THIS PROJECT

[divicbold47]

Hello maintainer, pls assign me this task