Provenance docs: making an app rebuildable from its own records

A project has good provenance when someone else could rebuild it from its documentation: the readme, design docs, schemas, and the recorded reasoning behind each feature, fix and refactor.

For every meaningful change: what was asked, why, which alternatives were considered, what was decided, and how it was verified. Keep schemas and state-management flows (reducers, message formats) written down as the source of truth rather than something to be read out of code.

Debugging gets faster because the reason behind odd code is written down. Onboarding gets easier. And when a part needs to be rewritten — say, porting DSP from the browser to C++ — the documentation describes the behaviour precisely enough to rebuild it and test the result against the original.