fix(background-agent): stabilize parent wakes

src/features/background-agent/manager.ts

@@ -109,6 +109,7 @@ type PendingParentWake = {
   notifications: string[]
   shouldReply: boolean
   dispatchedAt?: number
+  toolCallDeferralStartedAt?: number
 }
 
 type ParentWakeSessionMessage = {
@@ -145,6 +146,7 @@ type ResumeTaskSnapshot = {
 const PENDING_PARENT_WAKE_RETRY_MS = 1_000
 const PENDING_PARENT_WAKE_DEBOUNCE_MS = 100
 const PARENT_WAKE_ACCEPTED_MESSAGE_SKEW_MS = 5_000
+const PARENT_WAKE_TOOL_CALL_DEFER_MAX_MS = 5_000
 
 interface MessagePartInfo {
   id?: string
@@ -1380,6 +1382,9 @@ The fallback retry session is now created and can be inspected directly.
       notifications: [...wake.notifications],
       shouldReply: wake.shouldReply,
       ...(wake.dispatchedAt !== undefined ? { dispatchedAt: wake.dispatchedAt } : {}),
+      ...(wake.toolCallDeferralStartedAt !== undefined
+        ? { toolCallDeferralStartedAt: wake.toolCallDeferralStartedAt }
+        : {}),
     }
   }
 
@@ -1410,6 +1415,8 @@ The fallback retry session is now created and can be inspected directly.
       return false
     }
 
+    await settleAfterSessionIdle()
+
     if (await this.hasAcceptedMessageAfterDispatchedParentWake(sessionID, wake)) {
       this.clearDispatchedParentWake(sessionID)
       log("[background-agent] Ignored late parent wake failure after assistant output:", {
@@ -1425,6 +1432,7 @@ The fallback retry session is now created and can be inspected directly.
       pendingWake.notifications.unshift(...wake.notifications)
       pendingWake.shouldReply = pendingWake.shouldReply || wake.shouldReply
       pendingWake.promptContext = wake.promptContext
+      pendingWake.toolCallDeferralStartedAt ??= wake.toolCallDeferralStartedAt
     } else {
       this.pendingParentWakes.set(sessionID, this.cloneParentWake(wake))
     }
@@ -1531,9 +1539,18 @@ The fallback retry session is now created and can be inspected directly.
     ) ?? false
   }
 
-  private async shouldDeferParentWakeForSessionHistory(sessionID: string): Promise<boolean> {
+  private async shouldDeferParentWakeForSessionHistory(sessionID: string, wake: PendingParentWake): Promise<boolean> {
     const messages = await this.loadParentWakeSessionMessages(sessionID)
     if (!this.latestAssistantTurnIsWaitingOnTools(messages)) {
+      delete wake.toolCallDeferralStartedAt
+      return false
+    }
+    const now = Date.now()
+    wake.toolCallDeferralStartedAt ??= now
+    if (wake.shouldReply && now - wake.toolCallDeferralStartedAt >= PARENT_WAKE_TOOL_CALL_DEFER_MAX_MS) {
+      log("[background-agent] Sending parent wake after stale tool-call deferral window:", {
+        sessionID,
+      })
       return false
     }
     log("[background-agent] Deferred parent wake because latest assistant turn is waiting on tool results:", {
@@ -2694,15 +2711,16 @@ The task was re-queued on a fallback model after a retryable failure.
       return
     }
 
-    if (await this.shouldDeferParentWakeForSessionHistory(sessionID)) {
-      this.schedulePendingParentWakeFlush(sessionID)
-      return
-    }
-
     const latestWake = this.pendingParentWakes.get(sessionID)
     if (!latestWake) {
       return
     }
+
+    if (await this.shouldDeferParentWakeForSessionHistory(sessionID, latestWake)) {
+      this.schedulePendingParentWakeFlush(sessionID)
+      return
+    }
+
     this.pendingParentWakes.delete(sessionID)
 
     const notificationContent = latestWake.notifications.join("\n\n")
@@ -2733,6 +2751,7 @@ The task was re-queued on a fallback model after a retryable failure.
           pendingWake.notifications.unshift(...latestWake.notifications)
           pendingWake.shouldReply = pendingWake.shouldReply || latestWake.shouldReply
           pendingWake.promptContext = latestWake.promptContext
+          pendingWake.toolCallDeferralStartedAt ??= latestWake.toolCallDeferralStartedAt
         } else {
           this.pendingParentWakes.set(sessionID, latestWake)
         }
@@ -2751,6 +2770,7 @@ The task was re-queued on a fallback model after a retryable failure.
         pendingWake.notifications.unshift(...latestWake.notifications)
         pendingWake.shouldReply = pendingWake.shouldReply || latestWake.shouldReply
         pendingWake.promptContext = latestWake.promptContext
+        pendingWake.toolCallDeferralStartedAt ??= latestWake.toolCallDeferralStartedAt
       } else {
         this.pendingParentWakes.set(sessionID, latestWake)
       }