Phase 5d — Every Door in the Colony: cross-surface rollout

A guard is only as good as the number of doors it actually covers. Phase 5c defined how a lifecycle operation must treat a grounded fact; Phase 5d walks every door in the colony and wires it to that guard — six call sites across Studio, kontent, the API, and Flutter.

It was planned as clerical "wire six call sites" work. Grounding it told a different story: the surfaces had already diverged — the same lifecycle operation behaved differently on Studio than on the API — with live bugs to prove it, and not one call site ran in a transaction. That is exactly why the block-delete transactions and the five-bug cleanup were pulled forward into Phase 5a: 5d could only be a clean rollout once every call site was already correct and transactional.

The rollout, per the duplication ruling — each module adds assertions to its own cascade, and each speaks the refusal in its own idiom:

• API v1 — a plain DELETE that would orphan facts returns a 409 naming the blast radius; a deliberate DELETE …/blocks/{id}/cascade is the "yes, take the facts too" path.
• Studio — the human gets the blast-radius confirm modal: "this will affect N facts," then a second, explicit confirm before anything cascades. This was the last piece 5d shipped.
• kontent + API transitions — publish/archive detect their direction and fire the unarchive review, so a status change never silently resurrects a stale fact.
• Flutter — consumes the 409 as a modeled outcome, not a crash (the full treatment is Phase 5e).

By the end, ~85% of 5d was already satisfied by 5a and 5c; what remained was genuinely 5d's own — the per-surface 409 UX and the Studio confirm modal. The guard now covers every door, and each door tells the truth in the register its user expects.