Solidity Guard — instant static security lint

Deterministic static-security lint for Solidity: paste a contract, get a prioritized rule-based findings report (reentrancy ordering, unchecked calls, tx.origin, shadowing, pragma/visibility hygiene, pre-0.8 arithmetic) with line numbers in seconds. Fully deterministic - no LLM, no network egress, no data retention. Deliverable: markdown.