feat(grafana): swap Jaeger→Tempo, enable trace↔log correlation

compose.yml

@@ -712,7 +712,7 @@ services:
       - ./assets/icons/apple-touch-icon.png:/usr/share/grafana/public/img/apple-touch-icon.png:ro
     depends_on:
       - loki
-      - jaeger
+      - tempo
       - prometheus
     healthcheck:
       test:

infra/grafana/provisioning/datasources/datasources.yml

@@ -1,15 +1,30 @@
 apiVersion: 1
 datasources:
-  - name: Prometheus
-    type: prometheus
-    access: proxy
-    url: http://prometheus:9090
-    isDefault: true
   - name: Loki
     type: loki
     access: proxy
     url: http://loki:3100
-  - name: Jaeger
-    type: jaeger
+    uid: loki
+    isDefault: true
+    jsonData:
+      maxLines: 1000
+
+  - name: Prometheus
+    type: prometheus
     access: proxy
-    url: http://jaeger:16686
+    url: http://prometheus:9090
+    uid: prometheus
+    jsonData:
+      httpMethod: POST
+
+  - name: Tempo
+    type: tempo
+    access: proxy
+    url: http://tempo:3200
+    uid: tempo
+    jsonData:
+      tracesToLogsV2:
+        datasourceUid: loki
+        filterByTraceID: true
+      serviceMap:
+        datasourceUid: prometheus

tests/test_observability.py

@@ -150,3 +150,15 @@ class TestPrometheusTargets:
         assert "cadvisor" in jobs
         assert "nvidia-gpu" in jobs
         assert "jaeger" not in jobs
+
+
+class TestGrafanaDatasources:
+    def test_datasources_have_tempo_loki_default_correlation(self):
+        path = ROOT / "infra/grafana/provisioning/datasources/datasources.yml"
+        cfg = yaml.safe_load(path.read_text())
+        ds = {d["name"]: d for d in cfg["datasources"]}
+        assert "Tempo" in ds and "Jaeger" not in ds
+        assert ds["Loki"].get("isDefault") is True
+        tempo = ds["Tempo"]
+        assert tempo["jsonData"]["tracesToLogsV2"]["datasourceUid"] == "loki"
+        assert tempo["jsonData"]["serviceMap"]["datasourceUid"] == "prometheus"