fix(runtime): mux adapter forwards the dependency's real status code (05/STAB-19)

archreview/plans/R3-02-stale-good-family-plan.md

@@ -731,3 +731,13 @@ test could only pass once the production change landed.
 - The identical-value rule is honoured: the driver pushes **5.0 Good** before and after the outage, so the
   recovery assertion cannot be satisfied by a value change. The control (`InitialPush = null`) asserts
   `ExpectNoMsg` — no Good ever arrives — and that the audit fires with exactly 1 latched ref.
+
+### T12 — `DependencyConsumerMuxAdapter` forwards the real status code
+
+- RED: `--filter "…DependencyConsumerMuxAdapterTests"` ⇒ **2 failed**, both
+  `Shouldly.ShouldAssertException : consumer.Received[…].StatusCode should be 2150694912u` (0x80310000)
+  — the consumer received `0` (Good) for a `BadNoCommunication` input, on both the single and the batch
+  path. That is the finding, reproduced at the seam.
+- GREEN: 11 passed (`DependencyConsumerMuxAdapterTests` + `DependencyMuxActorTests`).
+- The false "quality is stripped at the mux boundary" comment is deleted and replaced with why it was
+  false (theme 6: the contract moved at #478/#519 and the comment outlived the fact).

archreview/plans/R3-02-stale-good-family-plan.md.tasks.json

@@ -87,7 +87,7 @@
     {
       "id": "T12",
       "subject": "DependencyConsumerMuxAdapter forwards the real StatusCode; delete the false 'quality is stripped' comment (05/STAB-19)",
-      "status": "pending",
+      "status": "done",
       "blockedBy": []
     },
     {