feat(background-agent): integrate team-mode into background manager

src/features/background-agent/manager.ts

@@ -407,6 +407,7 @@ export class BackgroundManager {
         spawnDepth: spawnReservation.spawnContext.childDepth,
         parentSessionId: input.parentSessionId,
         parentMessageId: input.parentMessageId,
+        teamRunId: input.teamRunId,
         parentModel: input.parentModel,
         parentAgent: input.parentAgent,
         parentTools: input.parentTools,
@@ -590,7 +591,7 @@ export class BackgroundManager {
       parentID: input.parentSessionId,
     })
 
-    if (this.onSubagentSessionCreated && this.tmuxEnabled && isInsideTmux()) {
+    if (!input.suppressTmuxSpawn && this.onSubagentSessionCreated && this.tmuxEnabled && isInsideTmux()) {
       log("[background-agent] Invoking tmux callback NOW", { sessionID })
       await this.onSubagentSessionCreated({
         sessionID,
@@ -602,7 +603,9 @@ export class BackgroundManager {
       log("[background-agent] tmux callback completed, waiting 200ms")
       await new Promise(r => setTimeout(r, 200))
     } else {
-      log("[background-agent] SKIP tmux callback - conditions not met")
+      log("[background-agent] SKIP tmux callback - conditions not met", {
+        suppressTmuxSpawn: !!input.suppressTmuxSpawn,
+      })
     }
 
     if (this.tasks.get(task.id)?.status === "cancelled") {
@@ -1507,6 +1510,19 @@ The fallback retry session is now created and can be inspected directly.
       canRetry,
     })
 
+    const sessionId = task.sessionId
+    if (sessionId) {
+      const sessionStillAlive = await this.verifySessionExists(sessionId)
+      if (sessionStillAlive) {
+        log("[background-agent] session.error received but session still alive, treating as transient:", {
+          taskId: task.id,
+          sessionId,
+          errorMessage: errorMsg?.slice(0, 200),
+        })
+        return
+      }
+    }
+
     if (task.currentAttemptID) {
       finalizeAttempt(task, task.currentAttemptID, "error", errorMsg)
     } else {