feat: add metrics for blocked events

Track and display blocked event counts with per-kind breakdown.

- Add events_blocked_total counter with kind label
- Add RecordBlockedEvent method to metrics
- Display blocked count in dashboard Storage section
- Call metric when rejecting non-core protocol kinds

Allows monitoring spam patterns and verifying kind filter effectiveness.
Raw metrics show breakdown by kind (e.g., kind=20001, kind=30311).

1 files changed, 7 insertions, 0 deletions

diff --git a/internal/metrics/dashboard.html b/internal/metrics/dashboard.html
index 9538ac6..1fa1ddf 100644
--- a/internal/metrics/dashboard.html
+++ b/internal/metrics/dashboard.html
@@ -199,6 +199,10 @@
                     <span class="metric-label">Deletions</span>
                     <span class="metric-value" id="event_deletions">0</span>
                 </div>
+                <div class="metric">
+                    <span class="metric-label">Blocked</span>
+                    <span class="metric-value" id="events_blocked">0</span>
+                </div>
             </div>
 
             <div class="card">
@@ -317,6 +321,9 @@
                 document.getElementById('event_deletions').textContent =
                     sumMetric(metrics, `${prefix}_relay_event_deletions_total`);
 
+                document.getElementById('events_blocked').textContent =
+                    sumMetric(metrics, `${prefix}_relay_events_blocked_total`);
+
                 const durationSum = sumMetric(metrics, `${prefix}_relay_request_duration_seconds_sum`);
                 const durationCount = sumMetric(metrics, `${prefix}_relay_request_duration_seconds_count`);
                 const avgLatencyMs = durationCount > 0 ? (durationSum / durationCount * 1000) : 0;