- Created server/services/DownloadBuilder.js with buildUserDownloads function
- Added private helpers: buildSeriesMapFromRecords, buildMoviesMapFromRecords, matchSabSlots, matchSabHistory, matchTorrents, getSlotStatusAndSpeed
- Updated server/routes/dashboard.js to use buildUserDownloads in /user-downloads and SSE /stream
- Removed ~500 lines of duplicated download-assembly logic
- All unit tests passing (DownloadBuilder: 14, DownloadAssembler: 73, TagMatcher: 26)
gronod