Give the link's liveness one owner

AGENTS.md

@@ -315,7 +315,7 @@ the file.
 
 ### [Internals and tests](docs/decisions.md#internals-and-tests)
 
-- #30 and #46 merged under the comprehension floor, and Locality is the next work.
+- #30, #46 and #48 merged under the comprehension floor, and Locality is the next work.
 - A listener that rejects is routed by Node's `captureRejections`, not by hand-dispatching.
 - The four-line abort dance is copied across `LinkLife`, `IdleWaiters`, `PendingRequests` and
   `SendWindow` rather than extracted.

docs/decisions.md

@@ -765,13 +765,15 @@ rule and an index of the titles below.
 
 ## Internals and tests
 
-- **#30 and #46 merged under the comprehension floor, and Locality is the next work.** Maintainer's call,
+- **#30, #46 and #48 merged under the comprehension floor, and Locality is the next work.** Maintainer's call,
   2026-09-27. A four-seat scoring run, depth 1, read the project at 6, 6, 7 and 6 (mean 6.25), every
   seat capped by Locality in the held-message and shutdown code #30 does not touch, where the floor
   is 7.0. The chunks after #30 lift Locality to 7 before any other work. Serves goal 8's
   reshapeable internals, which a reader has to understand before reshaping. Valid until a scoring
   run reads 7.0 or above. #46, maintainer's call 2026-09-28, merged as a step of that work at 6, 6, 7
   and 7, Locality 5, 5, 6 and 6, up from 6, 6, 7 and 6 and Locality 5, 5, 6 and 5 the same day.
+  #48, maintainer's call 2026-09-28, merged at 6, 6, 6 and 6, Locality 5 from every seat, on the
+  condition that the held-message flow is the next chunk.
 
 - **A listener that rejects is routed by Node's `captureRejections`, not by hand-dispatching.** Both
   emitters construct with `captureRejections: true` and implement

todo.md

@@ -207,7 +207,15 @@ hardest, and the held-message flow across `incoming-requests.ts`, `held-messages
 `Session`'s rejection handler second.
 
 - [ ] **Lift Locality to 7, and confirm it with a scoring run.** A run reading 7.0 or above also
-      retires the #30 and #46 decision.
+      retires the #30, #46 and #48 decision.
+
+- [ ] **Give the held-message flow one owner — next, the condition #48 merged under.** Whether a
+      message is still held, and so whether its receipt may pass the drain, is decided across
+      `IncomingRequests.emitSms()`, `HeldMessages.offer()`/`MessageHold`, `createSms()`'s handlers in
+      `sms.ts` and `Session`'s rejection handler, which finds the hold again through a `WeakMap`
+      keyed on the `Sms`; `MessageHold.answered()` defers its release a `setImmediate` so a
+      `sendDlr()` straight after `sendResp()` still counts as held. All four seats of the #48 run
+      ranked it second hardest; the inherited architect put it at about two days.
 
 ### Correctness