feat:Receiver adds a secure save button

Receiver adds a secure save button, used to save cache files during connection interruptions, making it convenient to resume transfers next time.
Button tooltip information added in multiple languages.

frontend/components/ClipboardApp.tsx

@@ -76,6 +76,7 @@ const ClipboardApp = () => {
     senderDisconnected,
     resetReceiverConnection,
     resetSenderConnection,
+    manualSafeSave,
   } = useWebRTCConnection({
     shareContent,
     sendFiles,
@@ -307,6 +308,7 @@ const ClipboardApp = () => {
               retrieveMessage={retrieveMessage}
               senderDisconnected={senderDisconnected}
               handleLeaveRoom={handleLeaveReceiverRoom}
+              manualSafeSave={manualSafeSave}
             />
           )}
         </CardContent>

frontend/components/ClipboardApp/FileListDisplay.tsx

@@ -40,6 +40,7 @@ interface FileListDisplayProps {
   onRequest?: (item: FileMeta) => void; // Request file
   onDelete?: (item: FileMeta) => void;
   onLocationPick?: () => Promise<boolean>;
+  onSafeSave?: () => void; // New prop for safe save functionality
   saveType?: { [fileId: string]: boolean }; // File stored on disk or in memory
   largeFileThreshold?: number;
 }
@@ -61,6 +62,7 @@ const FileListDisplay: React.FC<FileListDisplayProps> = ({
   onRequest,
   onDelete,
   onLocationPick,
+  onSafeSave,
   saveType,
   largeFileThreshold = 500 * 1024 * 1024, // 500MB default
 }) => {
@@ -380,6 +382,28 @@ const FileListDisplay: React.FC<FileListDisplayProps> = ({
                     {messages.text.FileListDisplay.chooseSavePath_dis}
                   </Button>
                 )}
+                {/* Safe Save Button - only show when location is picked and files are saved to disk */}
+                {onSafeSave &&
+                  pickedLocation &&
+                  (isAnyFileTransferring || 
+                   (saveType && Object.values(saveType).some(
+                     (isSavedToDisk) => isSavedToDisk
+                   ))) && (
+                    <Tooltip
+                      content={messages.text.FileListDisplay.safeSave_tooltip}
+                    >
+                      <Button
+                        onClick={() => {
+                          onSafeSave();
+                        }}
+                        variant="outline"
+                        size="sm"
+                        className="mr-2 text-green-600 border-green-600 hover:bg-green-50"
+                      >
+                        {messages.text.FileListDisplay.safeSave_dis}
+                      </Button>
+                    </Tooltip>
+                  )}
               </div>
             </div>
           )}

frontend/components/ClipboardApp/RetrieveTabPanel.tsx

@@ -39,6 +39,7 @@ interface RetrieveTabPanelProps {
     directoryHandle: FileSystemDirectoryHandle
   ) => Promise<void>;
   getReceiverSaveType: () => { [fileId: string]: boolean } | undefined;
+  manualSafeSave: () => void; // Add manual safe save function
   retrieveMessage: string;
   senderDisconnected: boolean;
   handleLeaveRoom: () => void;
@@ -63,6 +64,7 @@ export function RetrieveTabPanel({
   requestFolder,
   setReceiverDirectoryHandle,
   getReceiverSaveType,
+  manualSafeSave,
   retrieveMessage,
   senderDisconnected,
   handleLeaveRoom,
@@ -180,6 +182,7 @@ export function RetrieveTabPanel({
         onDownload={handleDownloadFile}
         onRequest={handleFileRequestFromPanel} // Use the panel's own handler
         onLocationPick={onLocationPick} // Use the panel's own handler
+        onSafeSave={manualSafeSave} // Add safe save handler
         saveType={getReceiverSaveType()}
       />
       {retrieveMessage && (