docs: point remaining Auth/observability GAPS items at issues (#20, ScadaBridge#81)

components/observability/GAPS.md

@@ -22,7 +22,7 @@ reach the shared `ZB.MOM.WW.Telemetry` library. Status legend: ⛔ gap · 🟡 p
 > listener, OTLP opt-in wiring) were **all subsequently executed the same day** — see the
 > "Follow-ons — DONE 2026-06-01" table at the bottom of this file, which this banner previously
 > contradicted (reconciled 2026-08-07). Only the operational items under "Still open" there
-> (deploying an OTel collector → #13; further ScadaBridge instruments) remain.
+> (deploying an OTel collector → #13; further ScadaBridge instruments → ScadaBridge#81) remain.
 
 ## Divergence vs spec
 
@@ -256,4 +256,4 @@ behaviour-preserving except the intentional, no-consumer-yet metric-shape change
 - **OTLP is opt-in but unexercised** (→ #13) until an OTel collector endpoint is deployed and the
   `<App>:Telemetry:Exporter=Otlp` + `:OtlpEndpoint` config is set. The wiring is in place; only a
   collector is missing.
-- **Further ScadaBridge instruments** beyond the first 4 are additive future work (not blocking).
+- **Further ScadaBridge instruments** beyond the first 4 are additive future work (not blocking). → ScadaBridge#81