Implement an automated C++ linter check that prevents the use of invariant within DDL coordinator code, as its use should be reserved for extremely rare cases where continuing execution is more dangerous than aborting the process, which should not occur in DDL coordinators.

As part of this ticket, audit all existing DDL coordinator code to identify any current uses of invariant and replace them with tassert to ensure consistent and safe error handling practices.

The linter should flag any future usage of invariant in DDL coordinator files or classes and provide guidance to use tassert instead, maintaining code safety and reliability.