Touba tutorial 1.0.0

Requirements: Touba, Node.js 24, POSIX shell (macOS/Linux/WSL).
See tutorial.md for SDK and service requirements.
Read the tutorial, then run: node validate.mjs
Published commands run in a new temporary directory, retained for inspection.
steps/ contains the exact sources in presentation order.
provenance.json identifies the sources; validation.json records your test and build.
Archive generation does not qualify a new build.
