fix: resolve WebSocket failure and crypto.randomUUID crash on HTTP/LXC

- Replace crypto.randomUUID() with a polyfill (generateUUID) that falls
  back to crypto.getRandomValues or Math.random — fixes crash on HTTP
  non-secure contexts where randomUUID is unavailable
- Fix WebSocket URL hardcoding port 8000 — use window.location.host so
  connections go through Nginx proxy in Docker/LXC instead of bypassing it
- Add /api/v1/status/ws/ location block in nginx.conf with WebSocket
  upgrade headers (must precede /api/ to avoid missing Upgrade header)

docker/nginx.conf

@@ -4,6 +4,16 @@ server {
     root /usr/share/nginx/html;
     index index.html;
 
+    # Proxy WebSocket (must be before /api/ to take priority)
+    location /api/v1/status/ws/ {
+        proxy_pass http://backend:8000;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+    }
+
     # Proxy API to backend
     location /api/ {
         proxy_pass http://backend:8000;
@@ -11,7 +21,7 @@ server {
         proxy_set_header X-Real-IP $remote_addr;
     }
 
-    # Proxy WebSocket
+    # Proxy legacy /ws/ path
     location /ws/ {
         proxy_pass http://backend:8000;
         proxy_http_version 1.1;