fix: make global default thresholds section always visible (addresses #433)

The collapsible chevron icon was confusing users who didn't realize they needed to expand the section to see the alert delay and threshold settings. Now the global defaults are always visible.

frontend-modern/src/components/Alerts/ThresholdsTable.tsx

@@ -59,7 +59,6 @@ interface ThresholdsTableProps {
 
 export function ThresholdsTable(props: ThresholdsTableProps) {
   const [searchTerm, setSearchTerm] = createSignal('');
-  const [showGlobalSettings, setShowGlobalSettings] = createSignal(false);
   const [editingId, setEditingId] = createSignal<string | null>(null);
   const [editingThresholds, setEditingThresholds] = createSignal<Record<string, number>>({});
   
@@ -582,28 +581,16 @@ export function ThresholdsTable(props: ThresholdsTableProps) {
     <div class="space-y-6">
       {/* Global Settings Section */}
       <div class="bg-white dark:bg-gray-800 border border-gray-200 dark:border-gray-700 rounded-lg shadow-sm">
-        <div 
-          class="p-4 flex items-center justify-between cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-900/50"
-          onClick={() => setShowGlobalSettings(!showGlobalSettings())}
-        >
+        <div class="p-4">
           <div>
             <h3 class="text-lg font-semibold text-gray-800 dark:text-gray-200">Global Default Thresholds</h3>
             <p class="text-sm text-gray-600 dark:text-gray-400 mt-1">
               Default thresholds that apply to all resources unless overridden
             </p>
           </div>
-          <svg 
-            class={`w-5 h-5 text-gray-500 transition-transform ${showGlobalSettings() ? 'rotate-180' : ''}`}
-            fill="none" 
-            stroke="currentColor" 
-            viewBox="0 0 24 24"
-          >
-            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" />
-          </svg>
         </div>
         
-        <Show when={showGlobalSettings()}>
-          <div class="border-t border-gray-200 dark:border-gray-700 p-4 space-y-4">
+        <div class="border-t border-gray-200 dark:border-gray-700 p-4 space-y-4">
             {/* Threshold table */}
             <div>
               <p class="text-xs text-gray-500 dark:text-gray-400 mb-3">
@@ -859,7 +846,6 @@ export function ThresholdsTable(props: ThresholdsTableProps) {
               </button>
             </div>
           </div>
-        </Show>
       </div>
       
       {/* Search Bar */}