fix: harden release checks for grouped routes

backend/tests/test_readiness_gate.py

@@ -1,6 +1,13 @@
 from pathlib import Path
 
 
+def test_backend_keeps_starlette_on_the_supported_pre_httpx2_line() -> None:
+    pyproject = Path(__file__).resolve().parents[1] / "pyproject.toml"
+    content = pyproject.read_text(encoding="utf-8")
+
+    assert '"starlette>=0.46.0,<1.0.0"' in content
+
+
 def test_readiness_gate_treats_deprecation_warnings_as_errors() -> None:
     script = Path(__file__).resolve().parents[2] / "scripts" / "run_readiness_check.sh"
     content = script.read_text(encoding="utf-8")