feat: add --foundry-deny flag to control forge diagnostic errors

[dguido]

Summary

Add --foundry-deny flag to control forge's diagnostic error level.

Problem

Forge's linter returns exit code 1 on warnings, causing crytic-compile to interpret this as a compilation failure even when Solidity compilation succeeded.

This breaks analysis of many Foundry projects that have linter warnings, including large projects like Optimism contracts-bedrock which has 113+ linter warnings.

Solution

• Add --deny never to forge build command by default
• Add --foundry-deny flag to allow users to override if needed

The --deny flag controls which forge diagnostics are treated as errors:

• never (default): No diagnostics cause errors
• warn: Warnings cause errors
• all: All diagnostics cause errors

Testing

Tested against Optimism contracts-bedrock which previously failed due to forge linter warnings. After this change, compilation succeeds and slither can analyze the contracts.

Changes

• crytic_compile/platform/foundry.py: Add --deny flag to forge build command
• crytic_compile/cryticparser/cryticparser.py: Add --foundry-deny CLI argument
• crytic_compile/cryticparser/defaults.py: Add default value

🤖 Generated with Claude Code

[elopez]

From what I can see, this is only supported since Foundry 1.4. We need to ensure we don't break support for older versions by using an unsupported CLI flag. I think a good way to go would be to make the current behavior the default (eg foundry_deny could have a None default), and when foundry_deny is None we don't add any extra arguments here. Alternatively, we could keep never as the default if you think that is more user friendly, but offer a way to disable the addition of --deny ... altogether (maybe a magic value such as "disable"?)