fix: resolve dashboard websocket 'disconnected' status

- Fixed status indicator UI mapping in websocket.js and index.html.
- Added missing CSS for connection status indicator and pulse animation.
- Made initial model registry fetch asynchronous to prevent blocking server startup.
- Improved configuration loading to correctly handle LLM_PROXY__SERVER__PORT from environment.

static/js/websocket.js

@@ -248,21 +248,19 @@ class WebSocketManager {
     }
 
     updateStatus(status) {
-        const statusElement = document.getElementById('ws-status-nav');
+        const statusElement = document.getElementById('connection-status');
         if (!statusElement) return;
         
-        const dot = statusElement.querySelector('.ws-dot');
-        const text = statusElement.querySelector('.ws-text');
+        const dot = statusElement.querySelector('.status-dot');
+        const text = statusElement.querySelector('.status-text');
         
         if (!dot || !text) return;
         
         // Remove all status classes
-        dot.classList.remove('connected', 'disconnected');
-        statusElement.classList.remove('connected', 'disconnected');
+        dot.classList.remove('connected', 'disconnected', 'error', 'connecting');
         
         // Add new status class
         dot.classList.add(status);
-        statusElement.classList.add(status);
         
         // Update text
         const statusText = {