v3.8.4 — aMule Completion via Gap Status

🐛 Fixed

• False-positive aMule "Download Complete" notifications when corrupted pieces transiently lifted byte counters past file size. The v3.8.2 isComplete flag for aMule downloads used bytes-equality on fileSizeDownloaded (= EC_TAG_PARTFILE_SIZE_DONE), which counts every byte received from peers including pieces that subsequently failed hash check before being discarded — so the counter could briefly meet or exceed fileSize while real file content was still missing, firing a downloadFinished event before the file was actually on disk. The check now derives completion from the lib's decoded gap status: an empty range list means every byte is hashed and written (the same computation aMule shows as "Verified & Written" in its UI). Read on the raw lib field before flattenRangePairs(), since that helper collapses both the empty and undefined cases to null.