Block deposits at the asset floor when live LPs exist

[clement-ux]

Summary

• block deposits at the native-liquidity floor when live LP shares still exist
• preserve the initial-deposit path when dead shares are the entire supply and no senior liabilities exist
• add regression coverage for a real asset loss with zero accrued fees and zero reserved withdrawals
• align the Ethena and Lido invariant deposit guards with the new insolvency condition
• harden Lido invariant handlers so mutated calldata remains ABI-decodable and strict mode runs with zero handler reverts

Security impact

A real market loss can reduce total assets to the MIN_LIQUIDITY floor without creating fees or reserved withdrawals. Before this change, a new depositor could mint most of the share supply at the floor price and capture a later recovery that belongs to existing LPs.

This is a follow-up to #288: that PR covered fee-driven insolvency, while this PR covers the separate asset-loss case.

Invariant harness

The Lido handlers accept full-word uint256 seeds and bound or derive narrower values internally. This prevents corpus mutations from producing non-canonical bool or narrow-integer ABI words that revert in the Solidity ABI dispatcher before handler execution. The handlers also reject zero-input dust cases and safely normalize full-width seeds and uint128 price-liquidity limits.

Testing

• Deposit tests: 16 passed, 0 failed
• Full suite excluding invariants: 532 passed, 0 failed, 3 skipped
• Ethena invariants with FOUNDRY_INVARIANT_FAIL_ON_REVERT=true: 256 runs, 12,800 calls, 0 reverts
• Lido invariants with FOUNDRY_INVARIANT_FAIL_ON_REVERT=true: 256 runs, 12,800 calls, 0 reverts

[naddison36]

Another good find

[naddison36]

post merge approve