Simplify C++!

PayloadOffset_t: A small type design challenge

Core Guidelines are not Rules

[fix dev diary] Week 6-7: Description and Issue ID

isValid()? Establish invariants and avoid zombie objects

[fix dev diary] Week 5: std::expected

[fix dev diary] Week 4: Closing in on core domain code

[fix dev diary] Week 3: create command and application service

[fix dev diary] Week 2: Foundation of the CLI App

[fix dev diary] Week 1: Preparations

Old new Project: Fix