Issue 298 and ADR 0246: a seat's new verb is promised before it is required

Design 33 said a seat's verbs change additively, and section 3 made each
one a condition of holding, so a verb added in the controller and served
from the catalogue could land in neither order. It happened three times on
2026-10-07. Section 7 now says the three steps and how each is checked.

00-META/glossary.md

@@ -53,7 +53,8 @@ is listed under [Homonyms](#homonyms), with the qualified form each domain uses.
   provision**, and its holder is then the mesh's answer for it when several modules provide it
   ([ADR 0126](../02-DECISIONS/0126-a-module-declares-its-own-seats.md)). The set, with who holds each
   seat, is the overview of what a mesh has ([26 — The seats](../03-DESIGN/01-to-be/26-the-seats.md)).
-  A seat carries **verbs** — the tools every holder must serve.
+  A seat carries **verbs** — the tools every holder must serve. A verb added to a held seat is first
+  promised as optional, then served, then required ([ADR 0246](../02-DECISIONS/0246-a-seats-new-verb-is-promised-before-it-is-required.md)).
 - **operator** — the person who runs the mesh, and the one the mesh talks to.
   *Not:* ~~master~~ (hq)
 - **person** — any human, as against the mesh acting unattended: *a person's word* releases a held