fix: dashboard prefix detection with Go runtime metrics

Bug: Dashboard showed zeros because it detected "go" as the prefix instead
of "muxstr" when Go runtime metrics appeared first in the metrics list.

Fix: Search for the first metric containing "_relay_" to properly detect
the namespace (muxstr, nostr-grpc, etc.) instead of using the first metric
in the alphabetical list.

Before: Object.keys(metrics)[0] → "go_gc_..." → prefix = "go"
After: Find metric with "_relay_" → "muxstr_relay_..." → prefix = "muxstr"

This fixes the dashboard displaying zeros when metrics data is present.

1 files changed, 2 insertions, 1 deletions

diff --git a/internal/metrics/dashboard.html b/internal/metrics/dashboard.html
index e7af48c..363f1f7 100644
--- a/internal/metrics/dashboard.html
+++ b/internal/metrics/dashboard.html
@@ -255,7 +255,8 @@
                 const text = await response.text();
                 const metrics = parsePrometheusMetrics(text);
 
-                const prefix = Object.keys(metrics)[0]?.split('_')[0] || 'muxstr';
+                const relayMetric = Object.keys(metrics).find(k => k.includes('_relay_'));
+                const prefix = relayMetric ? relayMetric.split('_relay_')[0] : 'muxstr';
 
                 document.getElementById('active_connections').textContent =
                     sumMetric(metrics, `${prefix}_relay_active_connections`);