feat(cron): add --account flag for multi-account delivery routing (#26284)

* feat(cron): add --account flag for multi-account delivery routing

Add support for explicit delivery account routing in cron jobs across CLI, normalization, delivery planning, and isolated delivery target resolution.

Highlights:
- Add --account <id> to cron add and cron edit
- Add optional delivery.accountId to cron types and delivery plan
- Normalize and trim delivery.accountId in cron create/update normalization
- Prefer explicit accountId over session lastAccountId and bindings fallback
- Thread accountId through isolated cron run delivery resolution
- Preserve cron edit --best-effort-deliver/--no-best-effort-deliver behavior by keeping implicit announce mode
- Expand tests for account passthrough/merge/precedence and CLI account flows

* cron: resolve rebase duplicate accountId fields

---------

Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/cron/isolated-agent/delivery-target.ts

@@ -42,8 +42,8 @@ export async function resolveDeliveryTarget(
   jobPayload: {
     channel?: "last" | ChannelId;
     to?: string;
-    sessionKey?: string;
     accountId?: string;
+    sessionKey?: string;
   },
 ): Promise<DeliveryTargetResolution> {
   const requestedChannel = typeof jobPayload.channel === "string" ? jobPayload.channel : "last";
@@ -101,11 +101,14 @@ export async function resolveDeliveryTarget(
   const mode = resolved.mode as "explicit" | "implicit";
   let toCandidate = resolved.to;
 
-  // When the session has no lastAccountId (e.g. first-run isolated cron
-  // session), fall back to the agent's bound account from bindings config.
-  // This ensures the message tool in isolated sessions resolves the correct
-  // bot token for multi-account setups.
-  let accountId = resolved.accountId;
+  // Prefer an explicit accountId from the job's delivery config (set via
+  // --account on cron add/edit). Fall back to the session's lastAccountId,
+  // then to the agent's bound account from bindings config.
+  const explicitAccountId =
+    typeof jobPayload.accountId === "string" && jobPayload.accountId.trim()
+      ? jobPayload.accountId.trim()
+      : undefined;
+  let accountId = explicitAccountId ?? resolved.accountId;
   if (!accountId && channel) {
     const bindings = buildChannelAccountBindings(cfg);
     const byAgent = bindings.get(channel);
@@ -115,11 +118,6 @@ export async function resolveDeliveryTarget(
     }
   }
 
-  // Explicit delivery account should override inferred session/binding account.
-  if (jobPayload.accountId) {
-    accountId = jobPayload.accountId;
-  }
-
   // Carry threadId when it was explicitly set (from :topic: parsing or config)
   // or when delivering to the same recipient as the session's last conversation.
   // Session-derived threadIds are dropped when the target differs to prevent

src/cron/isolated-agent/run.ts

@@ -317,8 +317,8 @@ export async function runCronIsolatedAgentTurn(params: {
   const resolvedDelivery = await resolveDeliveryTarget(cfgWithAgentDefaults, agentId, {
     channel: deliveryPlan.channel ?? "last",
     to: deliveryPlan.to,
-    sessionKey: params.job.sessionKey,
     accountId: deliveryPlan.accountId,
+    sessionKey: params.job.sessionKey,
   });
 
   const { formattedTime, timeLine } = resolveCronStyleNow(params.cfg, now);