Reapply "feat(observability): integrate NeMo Relay runtime and shared metrics"

Signed-off-by: Alex Fournier <afournier@nvidia.com>

tests/scripts/test_smoke_nemo_relay_shared_metrics.py

@@ -0,0 +1,41 @@
+"""Tests for the shared-metrics smoke artifact."""
+
+from pathlib import Path
+
+import pytest
+
+from scripts import smoke_nemo_relay_shared_metrics as smoke
+
+
+@pytest.mark.parametrize(
+    "relative_path",
+    [
+        Path(".venv") / "bin" / "hermes",
+        Path(".venv") / "Scripts" / "hermes.exe",
+    ],
+)
+def test_resolve_hermes_executable_from_repository_venv(
+    tmp_path,
+    monkeypatch,
+    relative_path,
+):
+    executable = tmp_path / relative_path
+    executable.parent.mkdir(parents=True)
+    executable.touch()
+    monkeypatch.setattr(smoke.shutil, "which", lambda _name: None)
+
+    assert smoke._resolve_hermes_executable(tmp_path) == executable
+
+
+def test_resolve_hermes_executable_falls_back_to_path(tmp_path, monkeypatch):
+    executable = tmp_path / "bin" / "hermes"
+    monkeypatch.setattr(smoke.shutil, "which", lambda _name: str(executable))
+
+    assert smoke._resolve_hermes_executable(tmp_path / "repo") == executable
+
+
+def test_resolve_hermes_executable_reports_missing_binary(tmp_path, monkeypatch):
+    monkeypatch.setattr(smoke.shutil, "which", lambda _name: None)
+
+    with pytest.raises(SystemExit, match="or on PATH"):
+        smoke._resolve_hermes_executable(tmp_path)