fix(frontend): use health.level for connected server count

The web UI was showing 8 connected servers instead of 13 because it
was using the legacy connected boolean field instead of health.level.

Added isServerConnected() helper that uses health.level === healthy
as the source of truth (per Spec 013), with fallback to legacy connected
field for backward compatibility.

This aligns the web UI with the tray and CLI which were fixed in the
previous commit.

Author: technicalpickles

frontend/src/stores/servers.ts

@@ -8,16 +8,30 @@ export const useServersStore = defineStore('servers', () => {
   const servers = ref<Server[]>([])
   const loading = ref<LoadingState>({ loading: false, error: null })
 
+  // Helper: Check if a server is considered "connected" using health.level as source of truth
+  // Falls back to legacy connected field for backward compatibility
+  function isServerConnected(server: Server): boolean {
+    // Spec 013: health.level is the single source of truth
+    if (server.health?.level === 'healthy') {
+      return true
+    }
+    // Fallback to legacy connected field if health is not present
+    if (!server.health) {
+      return server.connected
+    }
+    return false
+  }
+
   // Computed
   const serverCount = computed(() => ({
     total: servers.value.length,
-    connected: servers.value.filter(s => s.connected).length,
+    connected: servers.value.filter(isServerConnected).length,
     enabled: servers.value.filter(s => s.enabled).length,
     quarantined: servers.value.filter(s => s.quarantined).length,
   }))
 
   const connectedServers = computed(() =>
-    servers.value.filter(s => s.connected)
+    servers.value.filter(isServerConnected)
   )
 
   const enabledServers = computed(() =>