[pallaoro]

The media service's playable copies stop at 1080p. A video whose short side is above 1080 now uploads in parts to the service's own storage, which keeps the file as sent, and the service makes its playable copy from there. Exports do not read the original yet; that comes next.

• Browser: reads the picture size with the length, sends parts one at a time with a fresh link per try, resumes on retry, cancels cleanly.
• Falls back to the usual upload when the video is 1080p or less, the workspace has no room for originals, the browser cannot read the picture size, or not one part lands.
• Server: four routes under /api/assets/originals; the finished video joins the library like any upload.

Known gap: if the answer to the final join is lost after the service has joined the parts, a retry is refused and that video is not in the library.

315 unit tests, typecheck, build and the e2e suite pass (new block 17). Not yet run against the real storage.