Feat/improve ci

[maxnorm]

Summary

Improve CI

Changes Made

• add coverage action with report comment on PRs
• add slither (this one is failling, will see the results)
• update test

Checklist

Before submitting this PR, please ensure:

• Code follows the Solidity feature ban - No inheritance, constructors, modifiers, public/private variables, external library functions, using for directives, or selfdestruct

• Code follows Design Principles - Readable, uses diamond storage, favors composition over inheritance

• Code matches the codebase style - Consistent formatting, documentation, and patterns (e.g. ERC20Facet.sol)

• Code is formatted with forge fmt

• Tests are included - All new functionality has comprehensive tests

• All tests pass - Run forge test and ensure everything works

• Documentation updated - If applicable, update relevant documentation

Make sure to follow the CONTRIBUTING.md guidelines.

Additional Notes