Various fixes for desktop (#4976)

# Description of Changes
- ~Force classic logo~
- Refer to email instead of username in SaaS sign in flow
- Allow drag-and-drop files into desktop app
- Convert terminology & icons from upload/download to open/save in
desktop version

frontend/src/core/components/fileManager/EmptyFilesState.tsx

@@ -5,12 +5,16 @@ import { useTranslation } from 'react-i18next';
 import { useFileManagerContext } from '@app/contexts/FileManagerContext';
 import LocalIcon from '@app/components/shared/LocalIcon';
 import { BASE_PATH } from '@app/constants/app';
+import { useFileActionTerminology } from '@app/hooks/useFileActionTerminology';
+import { useFileActionIcons } from '@app/hooks/useFileActionIcons';
 
 const EmptyFilesState: React.FC = () => {
   const { t } = useTranslation();
   const { colorScheme } = useMantineColorScheme();
   const { onLocalFileClick } = useFileManagerContext();
   const [isUploadHover, setIsUploadHover] = useState(false);
+  const terminology = useFileActionTerminology();
+  const icons = useFileActionIcons();
 
   const handleUploadClick = () => {
     onLocalFileClick();
@@ -91,10 +95,10 @@ const EmptyFilesState: React.FC = () => {
             onClick={handleUploadClick}
             onMouseEnter={() => setIsUploadHover(true)}
           >
-            <LocalIcon icon="upload" width="1.25rem" height="1.25rem" style={{ color: 'var(--accent-interactive)' }} />
+            <LocalIcon icon={icons.uploadIconName} width="1.25rem" height="1.25rem" style={{ color: 'var(--accent-interactive)' }} />
             {isUploadHover && (
               <span style={{ marginLeft: '.5rem' }}>
-                {t('landing.uploadFromComputer', 'Upload from computer')}
+                {terminology.uploadFromComputer}
               </span>
             )}
           </Button>
@@ -105,7 +109,7 @@ const EmptyFilesState: React.FC = () => {
           className="text-[var(--accent-interactive)]"
           style={{ fontSize: '.8rem', textAlign: 'center' }}
         >
-          {t('fileUpload.dropFilesHere', 'Drop files here or click the upload button')}
+          {terminology.dropFilesHere}
         </span>
       </div>
     </div>

frontend/src/core/components/fileManager/FileActions.tsx

@@ -2,12 +2,16 @@ import React from "react";
 import { Group, Text, ActionIcon, Tooltip } from "@mantine/core";
 import SelectAllIcon from "@mui/icons-material/SelectAll";
 import DeleteIcon from "@mui/icons-material/Delete";
-import DownloadIcon from "@mui/icons-material/Download";
 import { useTranslation } from "react-i18next";
 import { useFileManagerContext } from "@app/contexts/FileManagerContext";
+import { useFileActionTerminology } from "@app/hooks/useFileActionTerminology";
+import { useFileActionIcons } from "@app/hooks/useFileActionIcons";
 
 const FileActions: React.FC = () => {
   const { t } = useTranslation();
+  const terminology = useFileActionTerminology();
+  const icons = useFileActionIcons();
+  const DownloadIcon = icons.download;
   const { recentFiles, selectedFileIds, filteredFiles, onSelectAll, onDeleteSelected, onDownloadSelected } =
     useFileManagerContext();
 
@@ -95,7 +99,7 @@ const FileActions: React.FC = () => {
           </ActionIcon>
         </Tooltip>
 
-        <Tooltip label={t("fileManager.downloadSelected", "Download Selected")}>
+        <Tooltip label={terminology.downloadSelected}>
           <ActionIcon
             variant="light"
             size="sm"

frontend/src/core/components/fileManager/FileSourceButtons.tsx

@@ -1,11 +1,12 @@
 import React from 'react';
 import { Stack, Text, Button, Group } from '@mantine/core';
 import HistoryIcon from '@mui/icons-material/History';
-import UploadIcon from '@mui/icons-material/Upload';
 import CloudIcon from '@mui/icons-material/Cloud';
 import { useTranslation } from 'react-i18next';
 import { useFileManagerContext } from '@app/contexts/FileManagerContext';
 import { useGoogleDrivePicker } from '@app/hooks/useGoogleDrivePicker';
+import { useFileActionTerminology } from '@app/hooks/useFileActionTerminology';
+import { useFileActionIcons } from '@app/hooks/useFileActionIcons';
 
 interface FileSourceButtonsProps {
   horizontal?: boolean;
@@ -17,6 +18,9 @@ const FileSourceButtons: React.FC<FileSourceButtonsProps> = ({
   const { activeSource, onSourceChange, onLocalFileClick, onGoogleDriveSelect } = useFileManagerContext();
   const { t } = useTranslation();
   const { isEnabled: isGoogleDriveEnabled, openPicker: openGoogleDrivePicker } = useGoogleDrivePicker();
+  const terminology = useFileActionTerminology();
+  const icons = useFileActionIcons();
+  const UploadIcon = icons.upload;
 
   const handleGoogleDriveClick = async () => {
     try {
@@ -76,7 +80,7 @@ const FileSourceButtons: React.FC<FileSourceButtonsProps> = ({
           }
         }}
       >
-        {horizontal ? t('fileUpload.uploadFiles', 'Upload') : t('fileUpload.uploadFiles', 'Upload Files')}
+        {horizontal ? terminology.upload : terminology.uploadFiles}
       </Button>
 
       <Button