Add Lucidly syUSD reserve adapter

[MyTH-zyxeon]

Summary

• add ILucidlyVault and LucidlyAdapter for parking excess USDC-style reserves into a Lucidly syUSD-style vault
• support configurable liquid reserve ratio, rebalance(), unpark(amount), epoch-based harvestYield(), and vault pause checks
• add MockLucidlyVault plus Foundry coverage for rebalancing, partial unpark, access control, pause handling, and yield harvest
• document the reserve parking flow in the README

Closes #20

Validation

• forge fmt --check contracts/interfaces/ILucidlyVault.sol contracts/extensions/LucidlyAdapter.sol contracts/mocks/MockLucidlyVault.sol forge-test/LucidlyAdapter.t.sol
• git diff --check
• FOUNDRY_LIBS=["node_modules","/tmp/codex-forge-libs"] FOUNDRY_TEST=forge-test forge test --match-contract LucidlyAdapterTest -vv (6 passed)
• FOUNDRY_LIBS=["node_modules","/tmp/codex-forge-libs"] FOUNDRY_TEST=forge-test forge test -vv (65 passed)
• npx hardhat compile (passes; local Node v25 unsupported warning from Hardhat)

Notes

• Tests use MockLucidlyVault only; no mainnet Lucidly calls are made.
• The interface intentionally stays narrow until the final Lucidly Arbitrum contract spec is confirmed.

[abhicris]

🤖 Audit verdict: safe

LucidlyAdapter implements standard ERC4626 vault integration with proper access control, safe asset handling (SafeERC20, balance-delta pattern), no malicious code, and no security vulnerabilities.

Audited by the kcolbchain PR pipeline. See pipeline docs.