feat: enhance CSV upload handling with chunked requests and token support; improve form input limits

frontend/src/components/SubHeaderAdmin.tsx

@@ -1,5 +1,5 @@
 import React from "react";
-import { Sheet, WholeWord } from "lucide-react";
+import { Sheet, WholeWord, Search } from "lucide-react";
 import { useState } from "react";
 import ImportGUI from "./ImportGUI";
 import { removeSelection } from "../utils/tableActions";
@@ -7,10 +7,17 @@ import { removeSelection } from "../utils/tableActions";
 type SubHeaderAdminProps = {
   setFiles: (files: File[]) => void;
   files?: File[];
+  search: string;
+  setSearch: (value: string) => void;
 };
 
 // Sub navigation bar for admin views: provides import + clear selection actions
-const SubHeaderAdmin: React.FC<SubHeaderAdminProps> = ({ setFiles, files }) => {
+const SubHeaderAdmin: React.FC<SubHeaderAdminProps> = ({
+  setFiles,
+  files,
+  search,
+  setSearch,
+}) => {
   const [showImport, setShowImport] = useState(false);
 
   return (
@@ -30,6 +37,17 @@ const SubHeaderAdmin: React.FC<SubHeaderAdminProps> = ({ setFiles, files }) => {
             </p>
           </div>
           <div className="flex items-center gap-2">
+            {/* Search */}
+            <div className="relative hidden sm:block">
+              <Search className="pointer-events-none absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-400" />
+              <input
+                type="text"
+                value={search}
+                onChange={(e) => setSearch(e.target.value)}
+                placeholder="Suchen… (Losnummer, Name, Adresse, PLZ, Email)"
+                className="w-72 rounded-md border border-gray-300 bg-white pl-9 pr-3 py-2 text-sm text-gray-900 placeholder-gray-400 shadow-sm focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500"
+              />
+            </div>
             <button
               onClick={() => setShowImport(true)}
               type="button"