feat: add auth rejection metrics to dashboard

Updated metrics dashboard to show:
- Unauthorized: Requests rejected due to pubkey not in allowlist
- Pre-Auth: Requests sent before authentication completed
- Challenges: Successful AUTH challenge completions

This surfaces the new 'unauthorized' and 'unauthenticated' request
status metrics on the dashboard for easier monitoring of auth issues.

1 files changed, 12 insertions, 5 deletions

diff --git a/internal/metrics/dashboard.html b/internal/metrics/dashboard.html
index 1fa1ddf..ab08eab 100644
--- a/internal/metrics/dashboard.html
+++ b/internal/metrics/dashboard.html
@@ -168,12 +168,16 @@
             <div class="card">
                 <h2>Authentication</h2>
                 <div class="metric">
-                    <span class="metric-label">Success</span>
+                    <span class="metric-label">Challenges</span>
                     <span class="metric-value" id="auth_success">0</span>
                 </div>
                 <div class="metric">
-                    <span class="metric-label">Failed</span>
-                    <span class="metric-value" id="auth_failure">0</span>
+                    <span class="metric-label">Unauthorized</span>
+                    <span class="metric-value" id="auth_unauthorized">0</span>
+                </div>
+                <div class="metric">
+                    <span class="metric-label">Pre-Auth</span>
+                    <span class="metric-value" id="auth_unauthenticated">0</span>
                 </div>
             </div>
 
@@ -305,8 +309,11 @@
                 document.getElementById('auth_success').textContent =
                     getMetricByLabel(metrics, `${prefix}_relay_auth_attempts_total`, 'result', 'success');
 
-                document.getElementById('auth_failure').textContent =
-                    getMetricByLabel(metrics, `${prefix}_relay_auth_attempts_total`, 'result', 'failure');
+                document.getElementById('auth_unauthorized').textContent =
+                    getMetricByLabel(metrics, `${prefix}_relay_requests_total`, 'status', 'unauthorized');
+
+                document.getElementById('auth_unauthenticated').textContent =
+                    getMetricByLabel(metrics, `${prefix}_relay_requests_total`, 'status', 'unauthenticated');
 
                 document.getElementById('rate_limit_hits').textContent =
                     sumMetric(metrics, `${prefix}_relay_rate_limit_hits_total`);