fix: improve alert threshold override persistence (addresses #295)

Frontend improvements:
- Store raw override config separately to handle delayed WebSocket state loading
- Use createEffect to reprocess overrides when WebSocket state becomes available
- Properly maintain raw config when adding/updating/removing overrides
- Ensures overrides don't disappear when switching tabs or navigating

This addresses the issue where custom thresholds would disappear after navigating
away from the tab, which was caused by the WebSocket state not being fully loaded
when the initial config was processed.

frontend-modern/src/pages/Alerts.tsx

@@ -95,6 +95,7 @@ export function Alerts() {
   let scheduleRef: ScheduleRef = {};
   
   const [overrides, setOverrides] = createSignal<Override[]>([]);
+  const [rawOverridesConfig, setRawOverridesConfig] = createSignal<Record<string, any>>({});  // Store raw config
   
   // Email configuration state moved to parent to persist across tab changes
   const [emailConfig, setEmailConfig] = createSignal<UIEmailConfig>({
@@ -131,6 +132,47 @@ export function Alerts() {
     } as EmailConfig;
   };
   
+  // Process raw overrides config when state changes
+  createEffect(() => {
+    const rawConfig = rawOverridesConfig();
+    if (Object.keys(rawConfig).length > 0 && state.nodes && state.vms && state.containers) {
+      // Convert overrides object to array format
+      const overridesList: Override[] = [];
+      
+      Object.entries(rawConfig).forEach(([key, thresholds]) => {
+        // Check if it's a node override by looking for matching node
+        const node = (state.nodes || []).find((n) => n.id === key);
+        if (node) {
+          overridesList.push({
+            id: key,
+            name: node.name,
+            type: 'node',
+            resourceType: 'Node',
+            thresholds: extractTriggerValues(thresholds)
+          });
+        } else {
+          // Find the guest by matching the full ID
+          const vm = (state.vms || []).find((g) => g.id === key);
+          const container = (state.containers || []).find((g) => g.id === key);
+          const guest = vm || container;
+          if (guest) {
+            overridesList.push({
+              id: key,
+              name: guest.name,
+              type: 'guest',
+              resourceType: guest.type === 'qemu' ? 'VM' : 'CT',
+              vmid: guest.vmid,
+              node: guest.node,
+              instance: guest.instance,
+              thresholds: extractTriggerValues(thresholds)
+            });
+          }
+        }
+      });
+      setOverrides(overridesList);
+    }
+  });
+
   // Load existing alert configuration on mount (only once)
   onMount(async () => {
     try {
@@ -163,40 +205,8 @@ export function Alerts() {
           setTimeThreshold(config.timeThreshold);
         }
         if (config.overrides) {
-          // Convert overrides object to array format
-          const overridesList: Override[] = [];
-          
-          Object.entries(config.overrides).forEach(([key, thresholds]) => {
-            // Check if it's a node override by looking for matching node
-            const node = (state.nodes || []).find((n) => n.id === key);
-            if (node) {
-              overridesList.push({
-                id: key,
-                name: node.name,
-                type: 'node',
-                resourceType: 'Node',
-                thresholds: extractTriggerValues(thresholds)
-              });
-            } else {
-              // Find the guest by matching the full ID
-              const vm = (state.vms || []).find((g) => g.id === key);
-              const container = (state.containers || []).find((g) => g.id === key);
-              const guest = vm || container;
-              if (guest) {
-                overridesList.push({
-                  id: key,
-                  name: guest.name,
-                  type: 'guest',
-                  resourceType: guest.type === 'qemu' ? 'VM' : 'CT',  // Check type property to determine VM or CT
-                  vmid: guest.vmid,
-                  node: guest.node,
-                  instance: guest.instance,
-                  thresholds: extractTriggerValues(thresholds)
-                });
-              }
-            }
-          });
-          setOverrides(overridesList);
+          // Store raw config to be processed when state is available
+          setRawOverridesConfig(config.overrides);
         }
         // Pass schedule config to schedule tab if it exists
         if (config.schedule && scheduleRef.setScheduleConfig) {
@@ -505,6 +515,8 @@ export function Alerts() {
             <ThresholdsTab 
               overrides={overrides}
               setOverrides={setOverrides}
+              rawOverridesConfig={rawOverridesConfig}
+              setRawOverridesConfig={setRawOverridesConfig}
               allGuests={allGuests}
               state={state}
               guestDefaults={guestDefaults()}
@@ -1074,11 +1086,13 @@ interface ThresholdsTabProps {
   storageDefault: () => number;
   timeThreshold: () => number;
   overrides: () => Override[];
+  rawOverridesConfig: () => Record<string, any>;
   setGuestDefaults: (value: Record<string, number> | ((prev: Record<string, number>) => Record<string, number>)) => void;
   setNodeDefaults: (value: Record<string, number> | ((prev: Record<string, number>) => Record<string, number>)) => void;
   setStorageDefault: (value: number) => void;
   setTimeThreshold: (value: number) => void;
   setOverrides: (value: Override[]) => void;
+  setRawOverridesConfig: (value: Record<string, any>) => void;
   activeAlerts: Record<string, Alert>;
   setHasUnsavedChanges: (value: boolean) => void;
 }
@@ -1321,10 +1335,22 @@ function ThresholdsTab(props: ThresholdsTabProps) {
                       props.setOverrides(props.overrides().map((o: Override) => 
                         o.id === override.id ? updatedOverride : o
                       ));
+                      // Update raw config too
+                      const newRawConfig = { ...props.rawOverridesConfig() };
+                      const hysteresisThresholds: Record<string, any> = {};
+                      Object.entries(updatedOverride.thresholds).forEach(([metric, value]) => {
+                        hysteresisThresholds[metric] = { trigger: value, clear: Math.max(0, (value as number) - 5) };
+                      });
+                      newRawConfig[updatedOverride.id] = hysteresisThresholds;
+                      props.setRawOverridesConfig(newRawConfig);
                       props.setHasUnsavedChanges(true);
                     }}
                     onRemove={() => {
                       props.setOverrides(props.overrides().filter((o) => o.id !== override.id));
+                      // Update raw config too
+                      const newRawConfig = { ...props.rawOverridesConfig() };
+                      delete newRawConfig[override.id];
+                      props.setRawOverridesConfig(newRawConfig);
                       props.setHasUnsavedChanges(true);
                     }}
                   />
@@ -1355,6 +1381,14 @@ function ThresholdsTab(props: ThresholdsTabProps) {
             existingOverrides={props.overrides()}
             onAdd={(override) => {
               props.setOverrides([...props.overrides(), override]);
+              // Update raw config too
+              const newRawConfig = { ...props.rawOverridesConfig() };
+              const hysteresisThresholds: Record<string, any> = {};
+              Object.entries(override.thresholds).forEach(([metric, value]) => {
+                hysteresisThresholds[metric] = { trigger: value, clear: Math.max(0, (value as number) - 5) };
+              });
+              newRawConfig[override.id] = hysteresisThresholds;
+              props.setRawOverridesConfig(newRawConfig);
               props.setHasUnsavedChanges(true);
             }}
           />