C8-01 — dogfood CsdaStudioApp: phases 8, 9 and 10 of 10

Drive `REQ-001`…`REQ-014` on `csda-studio-app` with the harness, review the branches, tag and deploy. ### Why this and C8-02 pay more than their own value They are the only two sources that have ever produced real harness defects. The ten in §12.11 of the closure plan came from here. `H14` came from reading the packs that feed both. Everything shipped in 0.7.0 — the write-scope guard, the message-protocol gate, readiness, the run ceiling — was built from defects found this way, and none of it has been run against this project since. ### Read first `mejoras/csda-studio-handoff.md` carries the live phase marker. --- *Filed while cutting 0.7.0.*