export bao client-cert not_before/not_after gauges and alert past 80% of lifetime

swarm-review-classifier/src/cost.rs

@@ -171,6 +171,10 @@ fn build() -> Option<(SdkMeterProvider, Counters)> {
         .build();
     let provider = SdkMeterProvider::builder().with_reader(reader).build();
     let counters = counters(&provider);
+    swarm_cert_metrics::register(
+        &provider.meter("hyperhive.review_classifier"),
+        "review-classifier",
+    );
     Some((provider, counters))
 }