fix(editor): a crop of a video with wide pixels keeps what its frame showed

The browser reports such a video by its shown size and ffmpeg's crop counts stored pixels, so a
frame over the middle half of a 320 stored, 640 shown video kept the whole width. A crop now carries
the size it was measured on and is scaled to the file's own pixels. A spec from before it did is cut
as it always was. Also drops a stale note in downloads/quota.py: edit jobs are held to the cap.

frontend/src/modules/files/VideoEditor.tsx

@@ -226,14 +226,16 @@ export default function VideoEditor({ job, onClose }: { job: DownloadJob; onClos
   const willJoin = output === "join" && kept.length > 1;
   const reencode = cropOn || accurate;
 
-  const cropPx = (): { x: number; y: number; w: number; h: number } | undefined => {
+  const cropPx = (): EditSpec["crop"] => {
     const v = videoRef.current;
     const vw = v?.videoWidth || vdim.w;
     const vh = v?.videoHeight || vdim.h;
     if (!cropOn) return undefined;
     // crop fractions are relative to the picture (the overlay is anchored to it), so this is a
     // straight fraction→source-px scale; see cropGeometry for the even-rounding + in-bounds clamp.
-    return cropToSourcePx(crop, vw, vh) ?? undefined;
+    const px = cropToSourcePx(crop, vw, vh);
+    // The size they count in goes along: it is the shown one, and the file's own can differ.
+    return px ? { ...px, frame_w: vw, frame_h: vh } : undefined;
   };
 
   const create = useMutation({