fix: surface OTel and sentinel visibility gaps

scripts/src/platform-infra-observability/diagnose-code-agent-script.ts

@@ -1986,8 +1986,26 @@ service_path = {
     service: ("reached" if service in services else "missing")
     for service in expected_services
 }
-service_path["complete"] = all(service in services for service in expected_services)
+missing_services = [service for service in expected_services if service not in services]
+service_path["complete"] = len(missing_services) == 0
+observability_gap = {
+    "status": "complete" if len(missing_services) == 0 else "missing-service-spans",
+    "expectedServices": expected_services,
+    "seenServices": sorted(services),
+    "missingServices": missing_services,
+    "complete": len(missing_services) == 0,
+}
+if missing_services and ("hwlab-cloud-api" in services or identity.get("runId") not in (None, "") or identity.get("commandId") not in (None, "")):
+    candidates.insert(0, {
+        "code": "observability_gap_missing_service_spans",
+        "label": "observability gap",
+        "confidence": 0.76,
+        "summary": "The business trace is correlated to Code Agent context but is missing expected service spans; do not interpret the missing manager/runner spans as proof that those services were not involved.",
+        "evidence": observability_gap,
+    })
 facts = []
+if missing_services:
+    facts.append("observability gap: missing service spans " + ",".join(missing_services))
 if http_summary.get("actorForbidden"):
     facts.append("actor forbidden")
 terminal_status = agentrun.get("terminalStatus")
@@ -2014,6 +2032,7 @@ summary = {
         "actorForbidden": http_summary.get("actorForbidden"),
         "terminalStatus": terminal_status,
         "failureKind": agentrun.get("failureKind"),
+        "observabilityGap": observability_gap.get("status"),
     },
 }
 evidence = {
@@ -2041,6 +2060,7 @@ payload = {
     "spanCount": len(spans),
     "services": services,
     "servicePath": service_path,
+    "observabilityGap": observability_gap,
     "businessTraceIds": business_trace_ids[:20],
     "identity": identity,
     "agentrun": {