docs(changelog): OTLP metrics to Grafana — Jun 23 entry

changelog.mdx

@@ -22,6 +22,24 @@ export const STAGE_SELF_MANAGED_M66 = "$0.0001";
   agentsfleet is in **stealth-mode testing** and pre-production. APIs and agent behavior may change between releases without long deprecation windows. Email [agentsfleet@agentmail.to](mailto:agentsfleet@agentmail.to) if you want a hand calibrating an agent or to join as a design partner.
 </Tip>
 
+<Update label="Jun 23, 2026" tags={["What's new", "Bug fixes", "Observability"]}>
+  ## Grafana dashboards for token throughput, credit drain, and run latency
+
+  agentsfleetd now pushes metrics to Grafana Cloud, completing the OpenTelemetry triad next to the traces and logs it already exports. You can watch run-latency p95, token throughput by model, and credit-drain rate live in Grafana while the control-plane database stays out of the query path. A ready-made dashboard ships at `deploy/grafana/agent-observability.json`.
+
+  Metrics ride the same `GRAFANA_OTLP_*` environment the trace and log exporters use, so one credential triple now turns on all three signals. With it unset, the exporter stays off and says so in one startup log line. Billing is untouched: the wallet, charge ledger, and per-event breakdowns stay in Postgres, and a metric is emitted only after its charge commits.
+
+  ## What's new
+
+  - **Three series** — credit drained (by posture and model), token throughput (by direction: input, cached, output), and a run-latency histogram, plus a `samples_dropped` counter that reports the exporter's own health.
+  - **One credential triple** — `GRAFANA_OTLP_ENDPOINT`, `GRAFANA_OTLP_INSTANCE_ID`, and `GRAFANA_OTLP_API_KEY` now enable traces, logs, and metrics together.
+  - **Collector requirement** — metrics use OTLP delta temporality; run an OpenTelemetry Collector with the `deltatocumulative` processor in front of Grafana Cloud Mimir, or the panels read empty. The dashboard's deployment note spells this out.
+
+  ## Bug fixes
+
+  - **Traces and logs** — span names, attributes, and log bodies were emitted with a stray extra quote that produced invalid JSON Grafana could reject; both now send well-formed payloads, so Tempo and Loki receive the data reliably.
+</Update>
+
 <Update label="Jun 17, 2026" tags={["What's new", "UI"]}>
   ## The website explains agentsfleet as one resident-engineer loop