Poll private deployed agents by canonical URL

tests/test_template_init.py

@@ -12,6 +12,7 @@ from agent_builder.tools import (
     _BUILDER_STATE_FILE,
     _BUILDER_INTERNAL_PREFIX,
     _parse_manifest_json,
+    _deploy_poll_url,
     _deployment_drift_error,
     _files_from_tarball,
     _parse_supporting_skill_files,
@@ -356,6 +357,22 @@ class TemplateInitTests(unittest.TestCase):
 
         self.assertIn("no CP JWT", result["error"])
 
+    def test_deploy_poll_url_falls_back_to_private_canonical_route(self) -> None:
+        self.assertEqual(
+            _deploy_poll_url({"url": None}, "private-agent"),
+            "https://private-agent.a2acloud.io",
+        )
+        self.assertEqual(
+            _deploy_poll_url(
+                {
+                    "expected_url": "https://expected.a2acloud.io",
+                    "url": "https://public.a2acloud.io",
+                },
+                "private-agent",
+            ),
+            "https://expected.a2acloud.io",
+        )
+
 
 def _tarball(files: dict[str, str]) -> bytes:
     buf = io.BytesIO()