feat(dashboard): live GPU health scoring + real KPIs

- Added /metrics/gpu-health endpoint with live health scores (VRAM 40%, temp 30%, load 30%)
- Added /metrics/latency endpoint for dashboard KPIs
- Added GPU_LABELS for human-readable model names
- Dashboard v2: rewired to real data endpoints
  - KPI cards: GPUs online, circuit trips, avg latency, req/min, active requests
  - Health scores from actual gpu_health_score() function
  - Rolling 60-sample history chart (real data, no simulation)
  - Status: green/yellow/red based on tripped circuits
  - No CDN dependency (pure CSS)
  - Auto-refresh every 15s
- nginx: /dashboard/ serves static files with cache headers
- docker-compose: dashboard volume mount

Co-authored-by: Abiba <abiba@sysloggh.com>

nginx/nginx.conf

@@ -31,7 +31,7 @@ http {
         # Disable buffering for SSE streams
         proxy_buffering off;
 
-        # API — through router
+        # API  through router
         location /v1/ {
             proxy_pass http://router_api;
             proxy_http_version 1.1;
@@ -42,7 +42,14 @@ http {
             proxy_read_timeout 600s;
             proxy_buffering off;
         }
-location /admin/ {            proxy_pass http://router_api;            proxy_http_version 1.1;            proxy_set_header Host $host;            proxy_set_header X-Real-IP $remote_addr;            proxy_set_header Authorization $http_authorization;        }
+
+        location /admin/ {
+            proxy_pass http://router_api;
+            proxy_http_version 1.1;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header Authorization $http_authorization;
+        }
 
         # SSE streaming endpoint
         location /stream {
@@ -71,7 +78,15 @@ location /admin/ {            proxy_pass http://router_api;            proxy_htt
             proxy_set_header Authorization $http_authorization;
         }
 
-        # Dashboard
+        # Professional Dashboard (Phase 1-3) - Static HTML served via Nginx
+        location /dashboard/ {
+            alias /opt/inference-harness/dashboard/;
+            index dashboard.html;
+            add_header Cache-Control "public, max-age=3600";
+            add_header X-Content-Type-Options nosniff;
+        }
+
+        # Legacy Dashboard (root) - Proxy to Flask app
         location / {
             proxy_pass http://dashboard_ui;
             proxy_http_version 1.1;