fix(outbound): return error instead of silently redirecting to allowList[0] (#13578)

src/infra/heartbeat-runner.returns-default-unset.test.ts

@@ -198,7 +198,7 @@ describe("resolveHeartbeatDeliveryTarget", () => {
     });
   });
 
-  it("applies allowFrom fallback for WhatsApp targets", () => {
+  it("rejects WhatsApp target not in allowFrom (no silent fallback)", () => {
     const cfg: OpenClawConfig = {
       agents: { defaults: { heartbeat: { target: "whatsapp", to: "+1999" } } },
       channels: { whatsapp: { allowFrom: ["+1555", "+1666"] } },
@@ -209,9 +209,8 @@ describe("resolveHeartbeatDeliveryTarget", () => {
       lastTo: "+1222",
     };
     expect(resolveHeartbeatDeliveryTarget({ cfg, entry })).toEqual({
-      channel: "whatsapp",
-      to: "+1555",
-      reason: "allowFrom-fallback",
+      channel: "none",
+      reason: "no-target",
       accountId: undefined,
       lastChannel: "whatsapp",
       lastAccountId: undefined,