fix(batch): use blockhash(block.number - 1) in _tryBlockAndAggregate

[lau90eth]

Summary

_tryBlockAndAggregate was calling blockhash(block.number), which
always returns bytes32(0) on mainnet EVM — the current block's hash
is not yet available during execution.

The correct value is blockhash(block.number - 1), consistent with
the existing getLastBlockHash() implementation in the same contract.

Root Cause

blockhash(N) returns 0 when N >= block.number. The existing tests
passed only because Foundry's test environment populates block hashes
differently from production EVM.

Fix

• Multicall3From._tryBlockAndAggregate: block.number → block.number - 1
• Updated tests to assert the correct value

Testing

forge test --match-path contracts/test/batch/Multicall3From.t.sol

29 tests passed, 0 failed.