feat(cron): add cron.wrap_response config to disable delivery wrapping (#3807)

Adds a config option to suppress the header/footer text that wraps
cron job responses when delivered to messaging platforms.

Set cron.wrap_response: false in config.yaml for clean output without
the 'Cronjob Response: <name>' header and 'The agent cannot see this
message' footer.  Default is true (preserves current behavior).

tests/cron/test_scheduler.py

@@ -167,6 +167,32 @@ class TestDeliverResultWrapping:
         sent_content = send_mock.call_args.kwargs.get("content") or send_mock.call_args[0][-1]
         assert "Cronjob Response: abc-123" in sent_content
 
+    def test_delivery_skips_wrapping_when_config_disabled(self):
+        """When cron.wrap_response is false, deliver raw content without header/footer."""
+        from gateway.config import Platform
+
+        pconfig = MagicMock()
+        pconfig.enabled = True
+        mock_cfg = MagicMock()
+        mock_cfg.platforms = {Platform.TELEGRAM: pconfig}
+
+        with patch("gateway.config.load_gateway_config", return_value=mock_cfg), \
+             patch("tools.send_message_tool._send_to_platform", new=AsyncMock(return_value={"success": True})) as send_mock, \
+             patch("cron.scheduler.load_config", return_value={"cron": {"wrap_response": False}}):
+            job = {
+                "id": "test-job",
+                "name": "daily-report",
+                "deliver": "origin",
+                "origin": {"platform": "telegram", "chat_id": "123"},
+            }
+            _deliver_result(job, "Clean output only.")
+
+        send_mock.assert_called_once()
+        sent_content = send_mock.call_args.kwargs.get("content") or send_mock.call_args[0][-1]
+        assert sent_content == "Clean output only."
+        assert "Cronjob Response" not in sent_content
+        assert "The agent cannot see" not in sent_content
+
     def test_no_mirror_to_session_call(self):
         """Cron deliveries should NOT mirror into the gateway session."""
         from gateway.config import Platform