feature: Trend Detection & Alert Suppression Windows

VigilCareClinicalAPI/Observability/Metrics/ClinicalMetrics.cs

@@ -36,6 +36,16 @@ public sealed class ClinicalMetrics
         "escalations_total",
         "Total alert escalations processed through the DLQ escalation path.");
 
+    public readonly Counter TrendAlertsTotal = Metrics.CreateCounter(
+        "trend_alerts_total",
+        "Total RAPID_DETERIORATION alerts generated, labeled by observation code.",
+        labelNames: new[] { "observation_code" });
+
+    public readonly Counter AlertSuppressionsTotal = Metrics.CreateCounter(
+        "alert_suppressions_total",
+        "Total alert suppression windows set after acknowledgment.",
+        labelNames: new[] { "alert_type" });
+
     // --- Histograms ---
 
     // Measures the full ingest transaction: Redis cache lookup + alert evaluation +
@@ -53,6 +63,14 @@ public sealed class ClinicalMetrics
         "news2_scoring_duration_seconds",
         "Time to compute a NEWS2 score from Redis state.",
         new HistogramConfiguration
+        {
+            Buckets = new[] { 0.001, 0.005, 0.01, 0.025, 0.05, 0.1 }
+        });   
+        
+    public readonly Histogram TrendAnalysisDuration = Metrics.CreateHistogram(
+        "trend_analysis_duration_seconds",
+        "Time to evaluate trend for one observation.",
+        new HistogramConfiguration
         {
             Buckets = new[] { 0.001, 0.005, 0.01, 0.025, 0.05, 0.1 }
         });