feat: add shadow LangGraph orchestrator runtime

agent-run-gateway.mjs

@@ -289,6 +289,7 @@ export function createAgentRunGateway({
   conversationMemoryService = null,
   syncUserPagesOnSuccess = null,
   observePersonalMemoryOnSuccess = null,
+  observeWorkflowRun = null,
   isSessionExternallyBusy = null,
   validateRunDeliverables = null,
   retryDelaysMs = DEFAULT_RUN_RETRY_DELAYS_MS,
@@ -338,6 +339,39 @@ export function createAgentRunGateway({
     );
   }
 
+  function dispatchShadowObservation(input) {
+    if (typeof observeWorkflowRun !== 'function' || input.toolMode !== 'code') return;
+    setImmediate(() => {
+      void Promise.resolve()
+        .then(() => observeWorkflowRun(input))
+        .then(async (result) => {
+          if (!result?.observed) return;
+          await appendEvent(input.runId, 'workflow_shadow_completed', {
+            engine: result.engine ?? 'langgraph',
+            mode: result.mode ?? 'shadow',
+            configVersion: result.configVersion ?? null,
+            status: result.shadowRun?.status ?? null,
+            phase: result.shadowRun?.phase ?? null,
+          });
+        })
+        .catch(async (error) => {
+          console.warn(
+            '[AgentRun] workflow shadow observation failed:',
+            error instanceof Error ? error.message : error,
+          );
+          await appendEvent(input.runId, 'workflow_shadow_failed', {
+            code: String(error?.code ?? 'WORKFLOW_SHADOW_FAILED').slice(0, 128),
+            message: String(error instanceof Error ? error.message : error).slice(0, 1000),
+          }).catch((appendError) => {
+            console.warn(
+              '[AgentRun] workflow shadow failure event skipped:',
+              appendError instanceof Error ? appendError.message : appendError,
+            );
+          });
+        });
+    });
+  }
+
   async function appendRunSnapshot(runId) {
     if (!isRunStreamReplayEnabled()) return;
     const row = await getRunById(runId);
@@ -443,8 +477,19 @@ export function createAgentRunGateway({
       taskType: normalizedTaskType,
       forceDeepReasoning: Boolean(forceDeepReasoning),
     });
+    const createdRun = projectRun(await getRunById(runId));
+    dispatchShadowObservation({
+      runId,
+      requestId: normalizedRequestId,
+      userId,
+      sessionId: sessionId || null,
+      workflowName: 'code-run-v1',
+      userMessage: runMessage,
+      toolMode: normalizedToolMode,
+      taskType: normalizedTaskType,
+    });
     if (autoDispatch) dispatchRun(runId);
-    return projectRun(await getRunById(runId));
+    return createdRun;
   }
 
   async function prepareRunDeliverables({ userId, sessionId, runId, runStartedAtMs = null }) {