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, 4 insertions, 0 deletions

diff --git a/internal/handler/websocket/handler.go b/internal/handler/websocket/handler.go
index 8daa89f..35d0aea 100644
--- a/internal/handler/websocket/handler.go
+++ b/internal/handler/websocket/handler.go
@@ -33,6 +33,7 @@ type MetricsRecorder interface {
         DecrementSubscriptions()
         SetActiveSubscriptions(count int)
         RecordRequest(method, status string, duration float64)
+        RecordBlockedEvent(kind int32)
 }
 
 type RateLimiter interface {
@@ -302,6 +303,9 @@ func (h *Handler) handleEvent(ctx context.Context, conn *websocket.Conn, raw []j
         // Reject non-core protocol kinds (spam, ephemeral, chat)
         if !isAllowedKind(pbEvent.Kind) {
                 status = "ok"
+                if h.metrics != nil {
+                        h.metrics.RecordBlockedEvent(pbEvent.Kind)
+                }
                 h.sendOK(ctx, conn, event.ID, true, "rejected: kind not supported")
                 return nil
         }