feat: alert on exhausted transaction retries

deploy/monitoring/orbit.rules.yml

@@ -49,6 +49,14 @@ groups:
         annotations:
           summary: "Orbit is waiting for MySQL connections"
           description: "Correlate pool use with database locks, query latency and storage load before increasing the connection limit."
+      - alert: OrbitDBTransactionRetryExhausted
+        expr: increase(orbit_db_transaction_retry_exhausted_total{job="orbit"}[5m]) > 0
+        for: 1m
+        labels:
+          severity: warning
+        annotations:
+          summary: "Orbit exhausted a bounded MySQL transaction retry"
+          description: "Inspect lock waits, deadlocks and the original operation identity; this counter excludes ambiguous COMMIT responses and must not trigger blind replay."
       - alert: OrbitInvalidMetricUpdates
         expr: increase(orbit_observability_rejected_samples_total{job="orbit"}[5m]) > 0
         for: 1m