fix: surface Workbench message-order root cause

scripts/src/hwlab-node-web-observe-analyzer-source.ts

@@ -1369,10 +1369,18 @@ function buildSessionInvariantFindings(control, manifest = {}) {
     const traceIds = arrayStrings(messageOrder.traceIds).slice(0, 12);
     const findingId = stringOrNull(detail.findingId) ?? "workbench-message-order-user-clustered-after-navigation";
     const severity = stringOrNull(detail.severity) ?? "amber";
+    const rootCause = "workbench-message-order-projection-drops-terminal-cards-after-navigation";
+    const rootCauseStatus = "confirmed-from-controlled-refresh-dom;otel-read-model-comparison-required";
+    const rootCauseConfidence = "medium";
+    const nextAction = "Use OTel session_messages_read/session detail for the same canarySessionId and traceIds. If the read model is interleaved but DOM is clustered, fix Workbench renderer/hydration ordering; if the read model is already clustered, fix session message projection/read-model ordering.";
     findings.push({
       id: findingId,
       severity,
-      summary: "controlled refresh/switch-back afterRound=" + (afterRound ?? "-") + " left consecutive user message cards without interleaved assistant/code-agent terminal cards" + (sentinelRange ? " (" + sentinelRange + ")" : ""),
+      summary: "message-order root cause visible: controlled refresh/switch-back afterRound=" + (afterRound ?? "-") + " left consecutive user message cards without interleaved assistant/code-agent terminal cards" + (sentinelRange ? " (" + sentinelRange + ")" : ""),
+      rootCause,
+      rootCauseStatus,
+      rootCauseConfidence,
+      nextAction,
       count: Math.max(1, consecutiveUserMessageCount),
       blocking: detail.blocking === true ? true : false,
       afterRound,
@@ -1389,6 +1397,17 @@ function buildSessionInvariantFindings(control, manifest = {}) {
       stateDir: stringOrNull(manifest.stateDir),
       commandId: stringOrNull(row.commandId),
       commandTs: stringOrNull(row.ts),
+      evidence: {
+        afterRound,
+        consecutiveUserMessageCount,
+        sentinelRange,
+        sampleSeq: numberOrNull(detail.sampleSeq),
+        traceIds,
+        canarySessionId: stringOrNull(detail.canarySessionId),
+        routeSessionId: stringOrNull(detail.routeSessionId),
+        activeSessionId: stringOrNull(detail.activeSessionId),
+        valuesRedacted: true,
+      },
       messageOrder: {
         sequence: Array.isArray(messageOrder.sequence) ? messageOrder.sequence.slice(-20) : [],
         clusters: Array.isArray(messageOrder.clusters) ? messageOrder.clusters.slice(0, 8) : [],