Find what a spec does not decide

Review this spec for what it does not decide.

Produce three groups:

**A. Blocking** — cannot start without an answer. For each: the question, why it blocks, and **a recommended default so it can be answered with a yes.**

**B. Will surface during build** — answerable later, but note them now so they are not silently decided by whoever hits them first.

**C. Assumed** — things the spec treats as settled that may not be. *These are the dangerous ones: nobody asks, because nobody noticed there was a choice.*

Look specifically for:
- Error and empty states. Specs describe the success path and stop.
- Permissions — who can do this, and who can see the result
- What happens to existing data
- Limits — how many, how large, how often
- Concurrency — two people doing this at once
- Undo, edit, delete after the fact
- Where the boundary with the existing system sits

Then:
- Requirements that conflict with each other or with how the existing system behaves.
- Anything specified in a way that is far more expensive than an adjacent alternative. *Say so before building it* — the spec author often does not know the cost.
- What the spec asks for that is not testable as written.

Rules:
- *Ask only what genuinely blocks or risks rework.* A long question list gets ignored entirely.
- Do not redesign the feature. Report what is undecided.