@typeInfo is only showing public declaration. This is intended behavior
@hasDecl checks if the declaration exists and is accessible from the current scope.
If you want to iterate through functions of K it seems like your only option is to make the relevant functions public, or iterate through them in another way(for example if you have numbered names you can easily iterate through them with @hasDecl).
fmt.comptimePrint is intended to print to a comptime string. The naming might be a bit confusing, but this is in line with fmt.bufPrint printing to a supplied buffer and fmt.allocPrint printing to an allocated buffer.
@compileLog is the only intended way to print stuff at compile time.