docs(m3): reconcile the remaining docs with the settled design

Docs written before this thread still carried the three-source copy model and
the Call 2 fields it implied.

- REQUIREMENTS.md REVIEW-10: title and short description are deterministic; the
  description comes from the model or the server.
- CREATE.md: primary category declared before Call 2; deterministic copy; the
  prompt revision interface; the slug; auth row in out-of-scope.
- API.md: infer-content inputs and result are the long description only.
- UAT-PRACTICE.md: the walk no longer tells the owner to leave copy for
  templates.
- README.md: the deploy section duplicated docs/DEPLOYMENT.md and
  deploy/INVENTORY.md; it now points at them.
- DEPLOYMENT.md: the prompt seed is stated per METADATA-105.

Both gates pass.

docs/DEPLOYMENT.md

@@ -33,7 +33,8 @@ If access is broken, fix it here before touching compose. Do not commit credenti
 Precondition: the M3 scaffold exists on the branch being deployed — `frontend/Dockerfile`,
 `backend/Dockerfile`, and `deploy/.env` on the host. `main` currently
 has `frontend/Dockerfile` only; `backend/` lands with M3 implementation.
-Prompts live in SQLite (`docs/contracts/PROMPTS.md`); no prompt files ship with the image.
+Prompts live in SQLite with all revisions, seeded from the text in `docs/contracts/PROMPTS.md` §6 on
+first run; no prompt files ship with the image (`METADATA-105`).
 
 1. Push the branch to Gitea from the dev box.
 2. On the UAT host: