docs(openwebui): re-key the model rows at swap time; default is frank-archon

The picker's decoration rows carried two payload-swap drifts: frank-dragoon
still named halogen 0.16.2 (live 0.18.20) and frank-zealot build 10777 /
3x262,144 / MTP off (live build 12118 / 3x200,704 / draft-mtp armed). Worse,
their params.context.length values had swapped, so OpenWebUI advertised more
window than the zealot slot grants and gave up 61k tokens on dragoon. Live
rows re-keyed through the admin API and ui.default_models set to
frank-archon; the swap procedure in AGENTS.md now names the re-key step.

AGENTS.md

@@ -278,7 +278,10 @@ archive.
 **Swap the model. Do not instrument it.** A payload change is: edit the trio
 (env / serve script / unit) → `scripts/deploy.sh <host> --service <svc>` →
 `/health` answers → one chat turn, one tool call, and one vision probe on an
-endpoint that serves images. That is the entire procedure.
+endpoint that serves images → re-key that endpoint's OpenWebUI `model` row
+(`meta.description` + `params.context.length`, API door in [[OpenWebUI]]). That is
+the entire procedure — no deployer step touches `webui.db`, and a stale
+`context.length` makes OpenWebUI advertise a window the endpoint does not grant.
 
 - **No benchmarking unless Frank orders it.** No pre-swap baseline battery,
   no A/B arms, no decode/prefill ladders, no acceptance tables, no numbers