Wire the streaming primitives into the video send path. `loadVideo` now stages
the source onto a local disk path (stageSourceToDisk — hardlink/download),
hashes it in one streaming pass (hashFileStreaming), and returns a `fileSource`
instead of a full in-memory buffer; the main video sub-file PUTs through a
`FileChunkSource`, so a multi-GiB video never holds more than one 1 MiB chunk in
RAM. The thumbnail and the fingerprint (noByteFallback) fast path stay
byte-based and unchanged.
`runPuts` now sizes its fast-path / fast-only checks off `fileSource ?? bytes`
and resolves the highway session before opening the file handle (the handle's
owner, uploadHighwayHttp, must be the next call so its finally-close always
runs). A size+mtime guard re-checks the staged file before the PUT so a source
mutated mid-send fails cleanly rather than shipping bytes that disagree with the
already-sent hashes. The staged temp is released in every exit path.
Output is byte-identical to the buffered path (the OIDB fileInfo md5/sha1/size
and the uploaded bytes are unchanged); the old readFileSync-based
stageVideoSource is removed. Tests cover the disk path (fileSource not bytes,
streamed hash == buffered hash), cleanup on upload failure, and empty sources.
DrSmoothl
e83eb80f2c