feat: add AttachFileButton for uploading files from a prompt context rather than chat

This is pretty much a stripped down version of AttachFileMenu so ofc there is duplication across this new component and AttachFileMenu but I believe it outweighs the increased complexity that would come from attempting to handle both contexts within just AttachFileMenu in regards to ephemeral agents and the file handling hooks - though we could probably refactor this without too much hassle later on in the file upload unification push once things are more settled.

client/src/components/Prompts/Files/AttachFileButton.tsx

@@ -0,0 +1,101 @@
+import * as Ariakit from '@ariakit/react';
+import { EToolResources } from 'librechat-data-provider';
+import React, { useRef, useState, useMemo, useCallback } from 'react';
+import { FileUpload, DropdownPopup, AttachmentIcon } from '@librechat/client';
+import { FileSearch, ImageUpIcon, TerminalSquareIcon, FileType2Icon } from 'lucide-react';
+import { useLocalize } from '~/hooks';
+
+interface AttachFileButtonProps {
+  handleFileChange?: (event: React.ChangeEvent<HTMLInputElement>, toolResource?: string) => void;
+  disabled?: boolean | null;
+}
+
+const AttachFileButton = ({ handleFileChange, disabled }: AttachFileButtonProps) => {
+  const localize = useLocalize();
+  const isUploadDisabled = disabled ?? false;
+  const inputRef = useRef<HTMLInputElement>(null);
+  const [isPopoverActive, setIsPopoverActive] = useState(false);
+  const [toolResource, setToolResource] = useState<EToolResources | undefined>();
+
+  const handleUploadClick = useCallback((isImage?: boolean) => {
+    if (!inputRef.current) {
+      return;
+    }
+    inputRef.current.value = '';
+    inputRef.current.accept = isImage === true ? 'image/*' : '';
+    inputRef.current.click();
+    inputRef.current.accept = '';
+  }, []);
+
+  const dropdownItems = useMemo(() => {
+    return [
+      {
+        label: localize('com_ui_upload_image_input'),
+        onClick: () => {
+          setToolResource(EToolResources.image_edit);
+          handleUploadClick(true);
+        },
+        icon: <ImageUpIcon className="icon-md" />,
+      },
+      {
+        label: localize('com_ui_upload_ocr_text'),
+        onClick: () => {
+          setToolResource(EToolResources.ocr);
+          handleUploadClick();
+        },
+        icon: <FileType2Icon className="icon-md" />,
+      },
+      {
+        label: localize('com_ui_upload_file_search'),
+        onClick: () => {
+          setToolResource(EToolResources.file_search);
+          handleUploadClick();
+        },
+        icon: <FileSearch className="icon-md" />,
+      },
+      {
+        label: localize('com_ui_upload_code_files'),
+        onClick: () => {
+          setToolResource(EToolResources.execute_code);
+          handleUploadClick();
+        },
+        icon: <TerminalSquareIcon className="icon-md" />,
+      },
+    ];
+  }, [localize, handleUploadClick]);
+
+  const menuTrigger = (
+    <Ariakit.MenuButton
+      disabled={isUploadDisabled}
+      id="attach-file-button-menu"
+      aria-label="Attach File Options"
+      className="flex items-center gap-2 rounded-md border border-border-medium bg-surface-primary px-3 py-2 text-sm font-medium text-text-primary transition-colors hover:bg-surface-hover focus:outline-none focus:ring-2 focus:ring-primary focus:ring-opacity-50"
+    >
+      <AttachmentIcon className="h-4 w-4" />
+      {localize('com_ui_attach_files')}
+    </Ariakit.MenuButton>
+  );
+
+  return (
+    <FileUpload
+      ref={inputRef}
+      handleFileChange={(e) => {
+        handleFileChange?.(e, toolResource);
+      }}
+    >
+      <DropdownPopup
+        menuId="attach-file-button"
+        className="overflow-visible"
+        isOpen={isPopoverActive}
+        setIsOpen={setIsPopoverActive}
+        modal={true}
+        unmountOnHide={true}
+        trigger={menuTrigger}
+        items={dropdownItems}
+        iconClassName="mr-0"
+      />
+    </FileUpload>
+  );
+};
+
+export default React.memo(AttachFileButton);