test(otel): cover user_api_key_info redaction on spans

Fail without the fix (metadata.user_api_key_* and team attributes leak),
with flag-off controls proving metadata is untouched when redaction is
disabled.

tests/unit/integrations/test_opentelemetry_redaction.py

@@ -0,0 +1,63 @@
+"""Regression tests for ``redact_user_api_key_info`` in OTEL spans (#36758)."""
+
+from unittest.mock import MagicMock
+
+import pytest
+
+import litellm
+from litellm.integrations.opentelemetry import OpenTelemetry
+
+_USER_API_KEY_METADATA = {
+    "user_api_key_hash": "hashed-secret",
+    "user_api_key_user_id": "uid-123",
+    "user_api_key_user_email": "user@example.com",
+    "user_api_key_team_id": "team-456",
+}
+
+
+def _metadata_attribute_keys(redact: bool, monkeypatch: pytest.MonkeyPatch) -> list[str]:
+    monkeypatch.setattr(litellm, "redact_user_api_key_info", redact)
+    otel_logger = OpenTelemetry()
+    otel_logger.safe_set_attribute = MagicMock()
+    otel_logger._set_inference_identity_attributes = MagicMock()
+    otel_logger._set_service_tier_attributes = MagicMock()
+    otel_logger._capture_in_span = MagicMock(return_value=False)
+
+    otel_logger.set_attributes(
+        span=MagicMock(),
+        kwargs={
+            "litellm_params": {"custom_llm_provider": "openai"},
+            "standard_logging_object": {
+                "call_type": "completion",
+                "metadata": {**_USER_API_KEY_METADATA, "generation_name": "test-gen"},
+            },
+        },
+        response_obj=None,
+    )
+    return [call.kwargs["key"] for call in otel_logger.safe_set_attribute.call_args_list]
+
+
+def test_set_attributes_drops_user_api_key_metadata_when_redaction_enabled(monkeypatch):
+    attribute_keys = _metadata_attribute_keys(redact=True, monkeypatch=monkeypatch)
+
+    assert "metadata.generation_name" in attribute_keys
+    for key in _USER_API_KEY_METADATA:
+        assert f"metadata.{key}" not in attribute_keys
+
+
+def test_set_attributes_keeps_user_api_key_metadata_when_redaction_disabled(monkeypatch):
+    attribute_keys = _metadata_attribute_keys(redact=False, monkeypatch=monkeypatch)
+
+    for key in _USER_API_KEY_METADATA:
+        assert f"metadata.{key}" in attribute_keys
+
+
+@pytest.mark.parametrize("redact, expected_calls", [(True, 0), (False, 2)])
+def test_team_attributes_on_child_spans_respect_redaction(monkeypatch, redact, expected_calls):
+    monkeypatch.setattr(litellm, "redact_user_api_key_info", redact)
+    otel_logger = OpenTelemetry()
+    otel_logger.safe_set_attribute = MagicMock()
+
+    otel_logger._set_team_attributes_on_span(span=MagicMock(), team_id="team-456", team_alias="team-alias")
+
+    assert otel_logger.safe_set_attribute.call_count == expected_calls