feat: add new frontend components, MH batch worker, and gitignore rules

- Add all new Frontend source files (pages, components, hooks, utils)
- Add selenium_MHBatchPaymentCheckWorker.py and MHSinglePaymentCheckWorker.py
- Add install-steps-5-13.sh setup script
- Update .gitignore to exclude runtime/sensitive data (backups, uploads,
  chat-history, keys, downloads, generated .d.ts files) while keeping folders
- Add .gitkeep to preserve empty runtime folders in git

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Frontend/src/components/ui/tabs.jsx

@@ -0,0 +1,11 @@
+import * as React from "react";
+import * as TabsPrimitive from "@radix-ui/react-tabs";
+import { cn } from "@/lib/utils";
+const Tabs = TabsPrimitive.Root;
+const TabsList = React.forwardRef(({ className, ...props }, ref) => (<TabsPrimitive.List ref={ref} className={cn("inline-flex h-10 items-center justify-center rounded-md bg-muted p-1 text-muted-foreground", className)} {...props}/>));
+TabsList.displayName = TabsPrimitive.List.displayName;
+const TabsTrigger = React.forwardRef(({ className, ...props }, ref) => (<TabsPrimitive.Trigger ref={ref} className={cn("inline-flex items-center justify-center whitespace-nowrap rounded-sm px-3 py-1.5 text-sm font-medium ring-offset-background transition-all focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 data-[state=active]:bg-background data-[state=active]:text-foreground data-[state=active]:shadow-sm", className)} {...props}/>));
+TabsTrigger.displayName = TabsPrimitive.Trigger.displayName;
+const TabsContent = React.forwardRef(({ className, ...props }, ref) => (<TabsPrimitive.Content ref={ref} className={cn("mt-2 ring-offset-background focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2", className)} {...props}/>));
+TabsContent.displayName = TabsPrimitive.Content.displayName;
+export { Tabs, TabsList, TabsTrigger, TabsContent };