062d69dc2a
Upload multiple files at once in sequence. Add retry button for files that fail ## Summary * **What is the goal of this PR?** Add support for selecting multiple epub files in one go, before uploading them all to the device * **What changes are included?** Allow multiple selections to be submitted to the input field. Sends each file to the device one by one in a loop Adds retry logic and UI for easy re-trying of failed uploads Addresses #201 button now says "Choose Files", and shows the number of files you selected <img width="506" height="199" alt="image" src="https://github.com/user-attachments/assets/64b0b921-1e67-438e-9cd7-57d5466f2456" /> Shows which file is uploading: <img width="521" height="283" alt="image" src="https://github.com/user-attachments/assets/17b4d349-0698-4712-984c-b72fcdcb0918" /> Failed upload dialog: <img width="851" height="441" alt="image" src="https://github.com/user-attachments/assets/e8bf4aa6-d3d2-4c0b-9c7a-420e8c413033" /> <img width="834" height="641" alt="image" src="https://github.com/user-attachments/assets/656a9732-3963-4844-94e3-4d8736f6d9d5" />