Feat: Round Validation System Implementation

[No-bodyq]

closes #126

This PR adds comprehensive validation logic for the RoundConfig struct through the new validate_config function, along with a full suite of unit tests to ensure proper configuration rules are enforced.

Changes Made

• Implemented validate_config to check for invalid game configuration values:
  • Wager amount cannot be zero.
  • Solo mode must have exactly 1 player.
  • Player count must be between 1 and 50.
  • Cards per round must be between 1 and 100.
  • Card timeout must be greater than zero.
  • Challenge type/parameter validation:
    • Enforces required params based on challenge type.
    • Rejects extra params for challenges that don’t require them.
    • Ensures param values are non-zero when required.
    • Prevents params from being set for Random challenges.
    • Enforces both params for GenreAndDecade challenges.
• Created create_base_config helper to simplify test setup.
• Added full test coverage for all validation rules.

Testing

• Added unit tests covering all possible validation cases.
• Verified valid configurations pass and all invalid configurations return the correct error message.

[No-bodyq]

Kindly review @manlikeHB

[manlikeHB]

Thank you! LGTM!