- enqueue() no longer resets an active/verifying download back to QUEUED, so
the periodic update check and repeated taps can't trigger needless
re-downloads; when files are already downloaded & verified it installs
directly instead of re-running the pipeline.
- DownloadWorker only purges partial files on a genuine user cancellation;
system-initiated stops (lost connectivity, quota) keep partials and retry,
fixing downloads appearing to restart on a flaky network.
- Add NetworkType.CONNECTED constraint + exponential backoff and return
Result.retry() for transient/network failures (capped) instead of always
succeeding.
- Validate HTTP 206 before resuming a .tmp (overwrite on 200) and drop corrupt
files on verification failure so retries restart clean.
ada5a1f899