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/database-management/import-database-section.jsx

@@ -0,0 +1,116 @@
+import { useRef, useState } from "react";
+import { useMutation } from "@tanstack/react-query";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+import { Button } from "@/components/ui/button";
+import { Upload, UploadCloud } from "lucide-react";
+import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle, } from "@/components/ui/alert-dialog";
+import { useToast } from "@/hooks/use-toast";
+export function ImportDatabaseSection() {
+    const { toast } = useToast();
+    const fileInputRef = useRef(null);
+    const [selectedFile, setSelectedFile] = useState(null);
+    const [confirmOpen, setConfirmOpen] = useState(false);
+    const restoreMutation = useMutation({
+        mutationFn: async (file) => {
+            const formData = new FormData();
+            formData.append("file", file);
+            const token = localStorage.getItem("token");
+            const res = await fetch("/api/database-management/restore", {
+                method: "POST",
+                headers: token ? { Authorization: `Bearer ${token}` } : {},
+                body: formData,
+            });
+            if (!res.ok) {
+                const body = await res.json().catch(() => ({}));
+                throw new Error(body.error || "Restore failed");
+            }
+            return res.json();
+        },
+        onSuccess: () => {
+            toast({
+                title: "Database Restored",
+                description: "Database restored successfully. Redirecting to login...",
+            });
+            setSelectedFile(null);
+            if (fileInputRef.current)
+                fileInputRef.current.value = "";
+            // Clear auth token and reload so the user re-authenticates against the
+            // restored database. This is necessary because the restored data may have
+            // a different userId than the current JWT, which would cause all
+            // user-scoped queries to return empty results.
+            setTimeout(() => {
+                localStorage.removeItem("token");
+                window.location.href = "/";
+            }, 2000);
+        },
+        onError: (err) => {
+            toast({
+                title: "Restore Failed",
+                description: err.message,
+                variant: "destructive",
+            });
+        },
+    });
+    const handleFileChange = (e) => {
+        const file = e.target.files?.[0] ?? null;
+        setSelectedFile(file);
+    };
+    const handleImportClick = () => {
+        if (!selectedFile)
+            return;
+        setConfirmOpen(true);
+    };
+    const handleConfirm = () => {
+        setConfirmOpen(false);
+        if (selectedFile)
+            restoreMutation.mutate(selectedFile);
+    };
+    return (<>
+      <Card>
+        <CardHeader>
+          <CardTitle className="flex items-center space-x-2">
+            <UploadCloud className="h-5 w-5"/>
+            <span>Import Database</span>
+          </CardTitle>
+        </CardHeader>
+        <CardContent className="space-y-4">
+          <p className="text-sm text-gray-500">
+            Restore the database from a <span className="font-medium text-gray-700">.sql</span> or <span className="font-medium text-gray-700">.zip</span> backup file.
+            This will overwrite all existing data.
+          </p>
+
+          <div className="flex items-center gap-3">
+            <input ref={fileInputRef} type="file" accept=".sql,.zip" onChange={handleFileChange} className="block text-sm text-gray-600 file:mr-3 file:py-1.5 file:px-3 file:rounded file:border file:border-gray-300 file:text-sm file:bg-white file:text-gray-700 hover:file:bg-gray-50 cursor-pointer"/>
+          </div>
+
+          {selectedFile && (<p className="text-sm text-gray-500">
+              Selected: <span className="font-medium text-gray-800">{selectedFile.name}</span>{" "}
+              ({(selectedFile.size / 1024 / 1024).toFixed(1)} MB)
+            </p>)}
+
+          <Button onClick={handleImportClick} disabled={!selectedFile || restoreMutation.isPending} variant="destructive" className="flex items-center space-x-2">
+            <Upload className="h-4 w-4"/>
+            <span>{restoreMutation.isPending ? "Restoring..." : "Import & Restore"}</span>
+          </Button>
+        </CardContent>
+      </Card>
+
+      <AlertDialog open={confirmOpen} onOpenChange={setConfirmOpen}>
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>Restore database?</AlertDialogTitle>
+            <AlertDialogDescription>
+              This will overwrite <strong>all existing data</strong> with the contents of{" "}
+              <strong>{selectedFile?.name}</strong>. This action cannot be undone.
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>Cancel</AlertDialogCancel>
+            <AlertDialogAction onClick={handleConfirm} className="bg-red-600 hover:bg-red-700">
+              Yes, restore
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </>);
+}