fix(prometheus): require the model label before emitting a team gauge

The guard only required the team label. These gauges are team-and-model
scoped, so when `model` is excluded through prometheus label configuration
every model for a team collapses onto one series: a request for a model with
no configured limit retires the series a limited model published, and a
second limited model overwrites it.

Extends the existing team-label guard to require both labels, which is the
same reasoning already applied to the team label -- a series that cannot
attribute a limit to a specific team and model can neither be trusted nor
retired.

Reported by veria-ai on #37215.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

litellm/integrations/prometheus.py

@@ -2393,11 +2393,19 @@ class PrometheusLogger(CustomLogger):
         removal path of this file's own.
         """
         labelnames: Final = self.get_labels_for_metric(metric_name)
-        if UserAPIKeyLabelNames.TEAM.value not in labelnames:
-            # Without a team label the gauge collapses to one sample shared by
-            # every team, which cannot attribute a limit to anyone and cannot
-            # be retired. Publishing nothing beats publishing a number that
-            # silently belongs to whichever team wrote it last.
+        if (
+            UserAPIKeyLabelNames.TEAM.value not in labelnames
+            or UserAPIKeyLabelNames.v1_LITELLM_MODEL_NAME.value not in labelnames
+        ):
+            # This gauge is team-and-model scoped, so it needs both labels to
+            # identify what it is reporting. Without the team label it collapses
+            # to one sample shared by every team; without the model label, to one
+            # sample shared by every model of a team -- and then a request for an
+            # unlimited model retires the series a limited one published, while a
+            # second limited model overwrites it. Either way the series cannot
+            # attribute a limit to anyone and cannot be retired, so publishing
+            # nothing beats publishing a number that silently belongs to whichever
+            # request wrote it last.
             return
 
         labels: Final = prometheus_label_factory(

tests/unit/integrations/test_prometheus_team_rate_limit_metrics.py

@@ -445,6 +445,24 @@ def test_emits_nothing_when_the_team_label_is_excluded():
         getattr(logger, metric_name).remove.assert_not_called()
 
 
+def test_emits_nothing_when_the_model_label_is_excluded():
+    """
+    These gauges are team-and-model scoped, so without a model label every
+    model for one team collapses to a single sample. A request for a model
+    with no limit would then retire the series a limited model published, and
+    a second limited model would overwrite it -- the same reasoning that drops
+    the gauge when the team label is missing.
+    """
+    logger = _logger_with_mock_team_gauges()
+    logger.get_labels_for_metric = MagicMock(return_value=["team", "team_alias"])
+
+    _set_team_metrics(logger, _payload_with_headers(dict(ALL_TEAM_HEADERS)))
+
+    for metric_name in TEAM_RATE_LIMIT_METRICS:
+        getattr(logger, metric_name).labels.assert_not_called()
+        getattr(logger, metric_name).remove.assert_not_called()
+
+
 def test_excluded_labels_never_reach_team_gauge_labelnames():
     """
     `exclude_labels` is applied inside `get_labels_for_metric`, so the