Say once why the hold timer is not unref'd

src/link-gate.ts

@@ -110,8 +110,7 @@ export class LinkGate {
 				settle({ err: aborted() });
 			}
 
-			// Deliberately not unref()'d: a held request is awaited with a destroyed socket and no
+			// Not unref()'d: a held request is awaited with no other handle, so the process would exit unsettled.
-			// other handle, so an unref'd timer lets the process exit without ever settling it.
 			if (left > 0) timer = setTimeout(giveUp, left);
 
 			signal?.addEventListener('abort', onAbort, { once: true });

test/session-extras.test.ts

@@ -829,8 +829,6 @@ describe('LinkGate', () => {
 		assert.match(held.err?.message ?? '', /did not come back in time/);
 	});
 
-	// A held send is awaited with the socket destroyed, so an unref'd timer here lets a process whose
-	// only remaining work is that send exit without ever settling it, losing the message silently.
 	test('holds on a timer that keeps the process alive', async () => {
 		const gate = new LinkGate({ log: silentLog, timeout: 10_000 });
 		const timers = (): number => process.getActiveResourcesInfo().filter(name => name === 'Timeout').length;

todo.md

@@ -139,8 +139,9 @@ session message is a change to every call site.
       things — `LinkGate.deadline()` and `wait(deadline)` are a two-call protocol whose only failure
       mode is calling `deadline()` inside the loop, which nothing catches; `Session.linkDown()` is
       read from both sides of the seam; and `UnansweredError` sits in `pending-requests.ts`, which
-      never uses it, for the sole edge that makes `send-sms` import that module at all. Every one of these is unpublished, so it is a two-way
+      never uses it, for the sole edge that makes `send-sms` import that module at all. Every one of
-      door and belongs after 1.0.0. Raised by review, 2026-09-01.
+      these is unpublished, so it is a two-way door and belongs after 1.0.0. Raised by review,
+      2026-09-01.
 - [ ] **Does an intermediate delivery notification deserve to be a `dlr`?** `esm_class` message type
       `INTERMEDIATE_DELIVERY` (0x20) is classified as a message today, so a peer that reports
       non-final states with it hands the application a raw `id:… stat:ENROUTE` text as an inbound