feat(failover): add auto-failover master switch with proxy integration (#427)

* feat(failover): add auto-failover master switch with proxy integration

- Add persistent auto_failover_enabled setting in database
- Add get/set_auto_failover_enabled commands
- Provider router respects master switch state
- Proxy shutdown automatically disables failover
- Enabling failover auto-starts proxy server
- Optimistic updates for failover queue toggle

* feat(proxy): persist proxy takeover state across app restarts

- Add proxy_takeover_{app_type} settings for per-app state tracking
- Restore proxy takeover state automatically on app startup
- Preserve state on normal exit, clear on manual stop
- Add stop_with_restore_keep_state method for graceful shutdown

* fix(proxy): set takeover state for all apps in start_with_takeover

src/components/prompts/PromptListItem.tsx

@@ -36,9 +36,7 @@ const PromptListItem: React.FC<PromptListItemProps> = ({
         </div>
 
         <div className="flex-1 min-w-0">
-          <h3 className="font-medium text-foreground mb-1">
-            {prompt.name}
-          </h3>
+          <h3 className="font-medium text-foreground mb-1">{prompt.name}</h3>
           {prompt.description && (
             <p className="text-sm text-muted-foreground truncate">
               {prompt.description}

src/components/prompts/PromptPanel.tsx

@@ -114,10 +114,7 @@ const PromptPanel = React.forwardRef<PromptPanelHandle, PromptPanelProps>(
           ) : promptEntries.length === 0 ? (
             <div className="text-center py-12">
               <div className="w-16 h-16 mx-auto mb-4 bg-muted rounded-full flex items-center justify-center">
-                <FileText
-                  size={24}
-                  className="text-muted-foreground"
-                />
+                <FileText size={24} className="text-muted-foreground" />
               </div>
               <h3 className="text-lg font-medium text-foreground mb-2">
                 {t("prompts.empty")}