Feature Request: Resume partial transfer

Hi team,
Thanks a lot for this powerful app 🙏

Are we planning to implement the option to resume partial transfers ? We could have this option shown when a file already exists but there is size mismatch.

Following are the reasons why I believe we could add this features:

1. Save time and resources - Scenario: when a person is transferring 2GB file, and for some reason the transfer is interrupted after 1GB. Then the option to resume will be very beneficial
2. Since the person performing the transfer will know if they are sharing the same file or not. So, just deleting the partially received file and re-transferring the whole file is wasteful efforts. And, since the user will be deciding whether to "resume the transfer or not", it will be a safe thing.

A possible change to the working when receiving the data which could help this feature as well as the user:

• Currently - When a file is being received, we use the original file name itself
  • In this case, it is hard to differentiate if the file is partially received or fully received.
  • No way other than relying on the user to know whether there is a possibility of resuming a partial transfer or not
• Proposal - When receiving, we could use the file name as <NAME>.<SIZE_BYTES>.part (.part is the extension used by browsers when file download is in-progress), and once fully received, we could rename it to <NAME>
  • User can easily know if a file is partially received or fully received by just looking at the file name
  • When re-sending files that were interrupted, SIZE_BYTES in the file name can help know whether we should show the resume option to the user or not (thus reducing false positives to a great extent)

Review issue #169 and the existing send/receive transfer flow to determine how interrupted files and size mismatches are currently handled. Define the user-visible behavior for partial-file naming, resume choice, and final renaming before implementation. Done means interrupted transfers can be identified and resumed when appropriate, while completed files retain the original name.