Entry-point test: a config with no projects is named in the startup errors

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

tests/integration/test_entry_points.py

@@ -43,5 +43,5 @@ def test_dev_entry_point_refuses_to_start_unconfigured(tmp_path: Path) -> None:
     assert result.returncode == 2
     assert "cannot start" in result.stderr
     # All of them at once, not the first one it happened to reach.
-    for expected in ("state_db", "matrix.token", "gitea.repo"):
+    for expected in ("state_db", "matrix.token", "projects: must name at least one"):
         assert expected in result.stderr