For weight check wrong percentages used.
According to documentation minimum valid weight is 2/3 but you set minimum as 67% which is 2.01/3.

So if block has 2.005/3 votes, then your lite-client invalidate it

1) `new_key_block` function is not implemented fully. `validators` are not updated. See:
```
() update_validator_set(cell block, cell config34) impure inline {
;; TODO: Implement validator update logic
}
```

2) On `new_key_block` message in function `verify_block`, it is not checked that the block is key. No checks for `seqno` of new block.

3) `yarn jest --verbose`. Tests do not work at all. Compilation error. In tests empty cells (`beginCell().endCell()`) are used as block and signatures in positive and negative test =)

No check of public keys for duplicates. We can use one public key several times to get more then 2/3 of total weight

No correct checks. Barely started parsing, mostly LLM-generated