Ship a smaller installer that no longer carries ffmpeg.exe/ffprobe.exe
(the bulk of its size). On first run they are downloaded from a pinned
upstream archive (gyan 8.1.2), verified against a pinned SHA-256, and
unpacked with the OS tar.exe into the managed userData/bin dir -- the
same place as the self-updating yt-dlp, so they survive app updates and
portable re-extraction. A hard onboarding gate blocks the app until they
are present, with a "locate existing ffmpeg" folder-picker fallback for
offline machines and a Repair action in Settings > About.
The updater's streaming/checksum/redirect/idle-timeout download loop is
extracted to lib/verifiedDownload.streamVerifiedFile and shared by both
the app-installer download and the ffmpeg fetch; the updater's public
behaviour and error strings are unchanged (its boundary tests still pass).
No new npm dependency: extraction uses the System32 bsdtar resolved by
absolute path (audit F3).
Note: this commit also carries pre-existing, in-progress aria2c/network
and updater-token work that was already uncommitted in the working tree
and is entangled with the above in shared files (updater.ts, ipc.ts,
preload/index.ts, mockApi.ts, shared/ipc.ts, plus the settings/network
files and aria2c.exe). It was not cleanly separable by path, so it is
included here rather than split out.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
14 pinning tests lock downloadAppUpdate's security invariants (redirect
re-validation per hop, checksum refusal paths, SHA-256 verify + cleanup,
truncation, idle-timeout, cancel in both phases, progress) with a
scripted net.request fake; then the nested streaming block is extracted
verbatim into streamInstallerToFile. downloadAppUpdate is now a linear
pre-flight; B6 cancel-slot ownership stays with its module state via
onCancelReady/onSettled. Pins green before and after.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
debont80